Always start your Nissan Altima shuts down while driving diagnosis by looking to see if there are any stored trouble codes. They can provide valuable insight as to what system is causing your car to die.
Parts stores can scan it for you if you don’t have access to a scanner. But we don’t recommend driving anywhere until your Altima is fixed since dying at the wrong time can cause a collision.
More and more cars and trucks are coming with a feature that kills the engine at a stop light. If your engine shuts down until you let off the brakes or move the steering wheel, it’s normal. There’s usually a button that deactivates this feature, but you’ll have to push it every time you start your Altima.
Your Altima’s engine needs three things to run properly; air, fuel, and spark. If your motor runs fine and suddenly dies, one of these three things is abruptly taken away. In this case, it’s usually fuel.
The most common reason your car shuts off when driving is a lack of fuel. The most likely cause is an empty fuel tank aided by a fuel gauge that’s not as accurate as it looks. Even if it indicates there is fuel in there, bang on the tank. If it makes a hollow sound, it’s probably empty.
Turn the key from off to on. You should hear the fuel pump trying to prime your Altima’s engine. If you don’t hear any noise, that indicates a faulty fuel pump, which is covered in the next section.
This is what a priming fuel pump sounds like.
Another common reason that your Altima may be starving for fuel is a bad fuel pump. The fuel pump sends highly pressurized fuel to the fuel rails. The engine can die if the fuel pressure is not high enough to atomize the gasoline properly.
The fuel pump is often not monitored by the engine’s computer, which means it doesn’t activate the check engine light when trying to figure out why your car is randomly dying.
If the engine isn’t starting, turn the key to the on position and listen carefully. You should hear a whining noise. That’s the fuel pump priming the fuel system. If you hear nothing, that strongly indicates that the fuel pump is bad.
Since the fuel pump is in your Altima’s gas tank, you may want to get a second set of ears so you can be absolutely sure you don’t hear it. If you don’t hear it, you should manually check the fuel pressure at the fuel rails. If it is not as high as it should be, you either have a bad fuel pump, or the filter could be clogged.
The fuel pump may be going out sporadically. This would mean it’ll die on the road and fire back up even a few seconds later.
If your car has been running rough recently and randomly shuts off while driving, this might be a sign that you need to drain your fuel tank and get fresh gas. The gas in the fuel rail will need to be emptied as well.
Sour gas is one of the most common causes of a vehicle shutting off when driving. This is because gasoline can become contaminated with dirt, water, or other substances, which can cause your engine to shut off while driving.
Bad gas could be the issue if your Altima shuts off a few minutes after you last filled it up.
Gas can also go bad with age. Gas shouldn’t be allowed to sit for more than a few months without being used, and if it has been sitting for an extended period, it loses its combustibility.
Old gas can also contain deposits that cause your engine to shut off. If you are experiencing this issue with a Nissan Altima that has not been driven in a while, draining the fuel tank and replacing the gas is likely to help.
A clogged fuel filter will usually start by reducing fuel pressure. So, if your Altima ran fine at low RPM, but stumbled when pressing the gas, a clogged fuel filter could be a possibility.
Check the battery cables to ensure they are debris-free and are correctly bolted to the battery posts. Follow the black ground cable to whatever it is connected to. Ensure it is secure, and no corrosion or rust could keep it from making a solid ground connection.
The engine needs a solid ground to the chassis for your Altima’s various electrical systems to work. If that cable is corroded, there could be problems such as misfiring, slow/no starts, or even the engine dying while driving. This is a common cause of many “gremlins.”
If the battery light was on before your Altima’s engine died, suspect the alternator.
The alternator is responsible for charging the battery and keeping your Altima running. If the alternator goes bad, the vehicle will run off the battery’s power supply (which is there mostly for starting your car and as a backup reserve).
Once the battery has been depleted, the ignition system will no longer be able to fire properly. You should see a battery or alternator light long before the engine dies. If you didn’t see it, it’s doubtful that the alternator or battery is at fault. If you did see the warning light, have the alternator and battery tested at the parts store. Replace them as needed.
There should be stored trouble codes if this is the problem.
The crankshaft and camshaft sensors tell the engine where your Altima’s crank and cam are located in their 360° revolutions. If they stop reporting this data, even momentarily, your car will not know when to fire the spark plugs, and it’ll stop running.
The mass air flow sensor can also go bad. These sensors should trigger a trouble code if they have a problem through.
If the timing chain/belt jumped or broke. It can cause your Altima to stop running on the spot. You may have heard it slapping around as the engine died. Your car’s engine may or may not turn over after this happens. It won’t start.
If your Altima’s engine is locked up, it’ll probably make a clunking sound but won’t start. The most common reason for this to happen is a lack of oil.
Usually, there will be trouble codes stored that should provide clues as to what’s happening. You should start your diagnosis with them. In the absence of a check engine light, take a good hard look at the fuel pump. If that’s not the issue, we recommend having an experienced mechanic look at the problem. They’ll need to record the telemetry from the OBD2 system when the car does it again. Then, they’ll be able to determine which part of the vehicle has the problem.
Your Nissan Altima’s service engine soon light is there to let you know that some sort of problem has been detected with the vehicle. Any vehicles made in 1996 or newer use OBDII codes, which can easily be retrieved from a good code scanner. A flashing service engine soon light is telling you that something needs immediate attention.
If your service engine soon light is on, you’ll need to pull these trouble codes to see what is wrong with your Altima. The trouble codes don’t even necessarily mean that there is an engine problem. There could be a problem with the transmission, ABS, oxygen sensors, etc…
In order to pull these codes from your Altima, you’re going to need a diagnostic scanner. You can pick one up pretty inexpensively. Or, you can head to the local auto parts store. Most of them will be happy to hook a code scanner up and tell you why the service engine soon light is on, and provide you with the code number.
Once you have this information, then you can look into what is involved in fixing it. This site has an article for most of the popular trouble codes, such as P0300, P0171, P0420, etc. There are plenty of great articles and videos out there online to help you make repair decisions once you actually have the code.
You’ll see what typically causes the particular code to pop up, and what it would take to fix it. At that point you can determine whether or not it is in your realm of mechanical expertise to attempt the repair, or if you’ll need to throw in the towel and take it into a shop. Without these codes, you are truly in the dark.
The only way that you are going to be able to turn off the service engine soon light is to return your Nissan Altima to normal working order. There are no shortcuts. But, it may be worth taking a look at the gas cap. If it wasn’t screwed in tight, or seems to have a bad seal, tightening it and driving for a while may turn off the check engine light.
It is ok to drive with the check engine light on. Although, you should still have your Altima repaired as soon as possible. It is NOT OK to drive it when the service engine soon light is flashing. A flashing light is letting you know that something is so wrong that continued vehicle operation can lead to permanent damage.
Make sure to check the oil, brake fluid, and transmission fluid levels. Low oil can cause some trouble codes to flash related to VVT. You don’t want the engine to lock up. If you find that one of these fluids is super low, fill them up and take it into a shop and have the issue addressed right away.
Your Altima’s service engine soon light should not keep you from driving, but it also shouldn’t be ignored (unless flashing). Get those OBDII codes as soon as possible so you know what you are dealing with, and can make a decision on how to repair it.
One of the most common automotive problems is an exhaust leak. Leaking exhaust can be loud, smelly, and (depending on where the leak is coming from) dangerous. If your car has a leaking exhaust system, it should not be ignored.
A leaking exhaust system affects your vehicle in many ways. Here are the most common symptoms of an exhaust leak:
If you go too long without fixing your Altima’s exhaust leak, it is possible for it to do damage to the catalytic converter. Replacing the converter is expensive. Ignoring the leak can cost you way more in the long run.
It is not safe to drive with an exhaust leak if the exhaust smell is making its way inside of the vehicle itself. While exhaust does smell, Carbon Monoxide doesn’t.
If your vehicle has leaking exhaust, it can only be caused by some form of damage to the exhaust system itself. It’s always a good idea to take a look at the gaskets and connections in the exhaust system before looking for a failing pipe, manifold, muffler, or catalytic converter.
The job of the motor mount is to keep the vehicle from rattling to death, while keeping the engine in the engine bay. All of the symptoms of a bad motor mount are going to be related to vibration, and the motor moving from it’s proper location. That being said, here are the three most common symptoms of a bad motor mount.
The most noticeable symptom of a motor mount that is going bad is vibration. That is, more vibration than you would typically feel when you are driving the car or truck. You’ll know when it’s happening. It may not necessarily feel like the car is going to rattle apart, but it’s very noticeable.
This is the most prominent symptom of a bad engine mount, and the first one that you’ll typically notice. If it is left alone long enough, it’ll lead to hard clunking sounds, which we’ll cover next ↓.
An engine mount that has gone bad will begin to exhibit a clunking sound. This sound will be most noticeable when putting the vehicle in and out of gear, when the engine shifts, as well as when you accelerate or de-accelerate abruptly.
This clunking comes from the mount being worn and having enough play to move when the force suddenly changes. This clunking may be accompanied by, or lead to full on engine movement ↓.
If you are driving and you feel the engine banging around, that’s a sure indication that a motor mount has failed. Really, you shouldn’t drive a vehicle with a motor mount clunking or even vibrating. If you hear and feel the engine rolling around, it’s time to stop driving and have the motor mounts replaced immediately. It’s going to cause all sorts of collateral damage in there.
You can inspect the motor mounts and look to see if they have any free play. If you take a look at the engine as it goes in and out of gear, it is normal to observe some movement of the engine as it torques one way or the other. It is not normal for it to make a lot of noise, or move excessively. It is very difficult to tell that a motor mount is bad just by looking at it. That’s why it’s better to look for the signs of a bad motor mount, than to look at the mounts themselves.
Here are some ways of telling if your engine mount is bad just by looking for signs.
One of the best ways that you can tell that you have a bad motor mount is if it is drooping to one side. Engine’s are meant to be level. If it is tipping in any one direction, that is a very strong indication that you have a bad motor mount.
As your engine moves around the engine bay, it can cause an exhaust leak. Exhaust leaks are pretty easy to distinguish. A pinging or knocking sound coming from the exhaust is typical. This happens because there’s not a lot of free play in the exhaust.
There isn’t a lot of extra room in the modern engine compartment, which means that things can easily get cut or broken when they move. This is exactly what can happen to hoses and belts when a motor mount fails.
If you see the engine is damaged, and that there’s some corresponding damage on the frame, that is a telltale sign that you have a bad motor mount.
There are many reasons why motor mount can go bad. Here are the most common ones:
One of the most common reasons that a Motor mount will go bad is when it gets damaged in an accident. Even if it’s a minor fender bender, that will often be enough to cause some serious damage to the mount. That’s why even if you are in an accident and it’s not that bad, it’s always a good idea to take it into an alignment shop and have an alignment done at the minimum. You should really take it to a mechanic and have them take a look and make sure there’s nothing else wrong.
If you put enough mileage on a vehicle everything will eventually break. The motor mounts are no exception to that. This is particularly true because most motor mounts have rubber bushings, which will dry and crack as they age even without mileage being put on the vehicle. Some motor mounts are liquid filled. This provides Great vibration dampening, but when they go bad they go bad hard. You can usually tell they’ve gone bad, because they will be leaking fluid onto the frame. It’ll look like your engine mounts have an oil leak.
If your car has recently been in an accident, the motor mounts may have been replaced. But, that doesn’t mean that they were replaced properly. That’s why it’s important to find a good shop whenever you have a major repair done.
There’s no perfect answer to this question. It’s going to depend a lot on how often you drive, whether or not the vehicle’s ever been in a collision, and what the motor mount is made out of. The best thing that you can do is have them looked at whenever you’re getting your vehicle serviced. Although, you should reasonably expect it to last for at least seven years.
Good luck finding out what’s going on with your car. Just remember while bad motor mounts are common, there can be other causes that would make your vehicle vibrate. It can be something as simple as a misfiring engine. Although, you should get some sort of trouble code if that were the case.
Your engine is a giant pump. It pulls in air (where it is measured by the mass airflow sensor). The air is then guided into the cylinder where fuel is added and compressed. Once compressed, the mixture it is ignited by the spark plugs. It is then expelled through the exhaust, where it is then scrubbed by the catalytic converter before being sent through the exhaust pipe.
Before diving into our list of the most common reasons that an engine sputters, make sure to check for trouble codes if you have a check engine light on. This can radically reduce the time it takes you to diagnose the problem.
Any failure in the process listed above can lead to a sputtering engine. Here are the most likely causes of sputtering:
Your ignition system is more than just the spark plugs. It relies on data from the crank and cam sensors to time the spark properly. The coil or coil packs need to be strong. The spark plugs themselves can go bad over time. Although with a modern vehicle, it should be able to go near – 100,000 miles without the plugs showing much damage.
If you do have a problem with the ignition system, you’ll more than likely get a diagnostic trouble code that indicates that there is a problem with the ignition system, such as P0300 (Random Multiple Misfire) or P030X where X represents the exact cylinder that is misfiring.
If there is reason to believe that the ignition system has gone bad, take a look at the spark plugs first. They can tell you a lot about what is going on with the engine.
If the plugs look fine, check the spark plug wires (if so equipped), make sure that they look good (not dry rotted, not melted). An old trick that you can do to check them is to make sure that they are not bleeding spark. Wait until it is dark, turn off the headlights and check under the hood. If you see spark coming from the wires, replace them and hopefully that will solve the problem.
If the plug wires check out, you’ll need to test the coil packs themselves. You can do it with a voltmeter. Here’s a great video to help you with that.
The next item on the list would be the fuel system. The fuel system starts with the fuel pump, which will be in the gas tank. It sends fuel through the fuel lines and filter to your vehicle’s fuel injectors.
There needs to be enough fuel pressure for the fuel to properly atomize at the injectors. If there is not the engine will sputter like crazy, as it will be starved for fuel.
Most vehicles have a port to manually check the fuel pressure. That’s a great place to start. You’ll have to look up where it is for your particular model year and engine combo. But, they usually aren’t hard to access.
If the fuel pressure reading is below where it needs to be, checking and replacing the fuel filter would be the first thing to check. It’s easier to get to than the fuel pump. Otherwise, you’ll more than likely have to drop the tank and replace the fuel pump.
Before going through all of that though, make sure to inspect the fuel lines for any crimping or damage.
If the pressure looks good, you’ll need to determine if the injectors are clogged or leaking. Smell for gas right after running the engine. That’s a strong indication that a fuel injector is leaking. If it is leaking, consider it a fire hazard and don’t run the engine again until the injector has been replaced.
A bad catalytic converter will cause the engine to sputter. They scrub the exhaust to remove pollutants. When they go bad it causes all kinds of problems. The two most obvious signs that one has gone bad will be engine sputtering and a rotten egg smell.
If the catalytic converter has gone bad, it will show itself the most when you need power. When the engine is idling, it may not sputter at all. As it revs up, more exhaust is created at one time. This leads to a back pressure increase, which chokes the engine from the exhaust side.
You’ll need to replace the catalytic converter if it is clogged. The most common OBDII codes associated with this code are P0420 or P0430.
Keep your nose open you should smell a bad smell coming from a bad catalytic converter.
The mass airflow, or MAF, sensor checks the air volume and temperature as it enters the engine. It’s one of the most important sensor that a vehicle has. Just like the air filter that protects it, it can get dirty. When it gets dirty it can’t read the air entering the engine properly and your engine will sputter.
The mass airflow sensor is really easy to get to. It’ll be between the intake manifold and the air filter. If you do have to clean it, make sure that you are using mass airflow sensor cleaner, and nothing else. Otherwise you can damage it. Here’s a great video on how to properly clean a MAF sensor.
Engine sputtering is a tough problem to track down. The above list is not everything that can cause this problem, but it is a great start. If you find out what happened to cause your car to sputter, please come back and leave a comment. Good luck!
If you own a Nissan Altima, you may have encountered the P0102 trouble code. This code indicates that the Mass Air Flow (MAF) circuit is low and not performing within its specified operating range. When this happens, your car may experience drivability issues such as stalling, lack of power, rough idle, and hesitation.
There are several potential causes of the P0102 code, including a faulty or contaminated MAF sensor, debris blocking the air flow sensor element, vacuum leaks, a poorly closed air filter box, or an incorrect air filter installed.
If you encounter this code, it is important to diagnose and fix the problem promptly to avoid further damage to your car.
P0102: MAF Sensor – Circuit Low Voltage Input
Your Altima’s MAF sensor is responsible for metering the air as it enters the engine. The PCM (Powertrain Control Module) uses this data to adjust the air fuel mixture. The MAF is one of the most important sensors your Altima has.
When the MAF circuit is low, it means that the sensor is not performing within its specified operating range. Specifically, the voltage value is lower than the expected range.
This can cause a variety of issues, including reduced fuel economy, trouble starting the engine, and poor engine performance.
To diagnose and fix this issue, you will need to start by checking the possible causes listed below. This may involve cleaning or replacing your Altima’s MAF sensor, checking for air leaks, or repairing any electrical shorts.
If you are unsure how to proceed, it’s always best to take your Nissan Altima to a qualified mechanic who can diagnose and fix the issue for you. Ignoring the P0102 code can lead to more serious engine problems down the line, so it’s important to address it as soon as possible.
If your Nissan Altima is experiencing a P0102 trouble code, you may notice a variety of symptoms. Here are some of the most common symptoms associated with a P0102 code:
If you are experiencing the P0102 code in your Nissan Altima, there are a few potential causes to consider. Here are some of the most common causes of the P0102 code:
Here are some steps you can take to diagnose P0102 in your Nissan Altima.
Remember that the P0102 code may not always be the cause of your Altima’s performance issues. It’s important to perform a thorough diagnosis to identify any other potential issues that may be contributing to the problem.
If you have determined that your Nissan Altima has a P0102 code, there are a few steps you can take to repair the issue. Here are some options:
It is important to note that if you replace the MAF sensor, you should use an OEM Nissan (original equipment manufacturer) part. Aftermarket parts may not work as well and could cause additional issues.
If you are uncomfortable with performing any of these repairs yourself, it is best to take your vehicle to a certified mechanic. They can diagnose and repair the issue for you.
Remember, it is important to address the P0102 code as soon as possible. Ignoring the issue could lead to further damage to your vehicle and could cause more expensive repairs down the line.
P0101 code in the Nissan Altima is crucial to maintaining your car’s performance and ensuring it runs efficiently. This code indicates that there is a problem with your car’s Mass Air Flow (MAF) sensor, specifically, a Range/Performance issue.
When you encounter the P0101 code, it is essential to diagnose the problem and fix it as soon as possible. It can affect the way the engine runs, and in extreme cases, can be a breakdown risk.
Here we will discuss the causes, symptoms, and possible fixes for this code in your Altima, offering guidance on how to approach and resolve this common issue.
MAF Sensor – Circuit (Range/Performance)
The P0101 code indicates to an issue with the Mass Air Flow (MAF) sensor in your Nissan Altima. It’s a generic code, which means it has the same definition for your car as it would any other vehicle.
This diagnostic trouble code is triggered when the Engine Control Module (ECM) identifies an issue with the MAF sensor’s output signal, specifically when it falls outside the expected range.
The MAF sensor is essential for your vehicle’s performance, as it measures the amount of air entering the engine and adjusts the fuel mixture accordingly.
When your Nissan Altima experiences a P0101 code, you may notice several symptoms that indicate there is an issue with the Mass Air Flow (MAF) sensor. Some of these symptoms include:
When dealing with a P0101 code in your Nissan Altima, it is essential to understand the potential causes to accurately diagnose and resolve the issue. In this section, we will discuss some of the most common causes for this code.
One possible cause for the P0101 code in your Nissan Altima is a dirty air filter. A dirty air filter can restrict the airflow into the engine, causing the mass air flow (MAF) sensor to generate inaccurate readings.
To address this issue, you should regularly inspect and replace your air filter as necessary to ensure proper airflow and accurate sensor readings.
Another common cause of the P0101 code is a dirty or malfunctioning mass air flow (MAF) sensor. The MAF sensor measures the volume and density of air entering the engine, and if it becomes dirty or clogged, it can produce inaccurate readings.
To fix this issue, you should clean the MAF sensor with a suitable cleaner, or replace it if necessary. Only use a dedicated MAF cleaner. You can pick it up at any parts store, or even Wal-Mart. Otherwise, you can damage the MAF sensor’s delicate electronics.
Intake air leaks can also lead to the P0101 code in your Nissan Altima. These leaks can occur in various areas, including the intake manifold, throttle body gasket, or vacuum hoses.
To identify and repair any intake air leaks, you should carefully inspect your vehicle’s intake system to locate any visible damage, and replace or repair any faulty components as needed. You can use carb cleaner to spray it
Lastly, issues with the MAF sensor’s wiring harness or electrical connections could also trigger the P0101 code. In this case, you should inspect the wiring and connections for any signs of damage, corrosion, or looseness, and address any issues found accordingly.
By understanding and addressing these possible causes, you can effectively diagnose and fix the P0101 code in your Nissan Altima, ensuring a smooth and efficient running engine.
To diagnose and fix the P0101 issue in your Nissan Altima, you should start by examining the MAF sensor and related components for any visible signs of malfunction.
If necessary, use an OBD scan tool to further investigate the problem. Remember to address this issue promptly, as extended driving with a P0101 code can potentially result in internal engine damage or catalytic converter failure.
The following steps can help you diagnose and potentially fix the P0101 code:
By taking these steps to address the P0101 code in your Nissan Altima, you can maintain your vehicle’s performance and potentially avoid more serious engine damage.
P0101 is a common OBDII code that indicates an issue with the Nissan Altima’s MAF sensor.
There are several potential causes for a P0101 code in your Nissan Altima. Some of these causes include:
A bad fuel pump can cause a myriad of problems for your Nissan Altima, making it essential to be aware of the warning signs that indicate trouble.
Your fuel pump is responsible for pushing fuel from your car’s fuel tank to the engine, but when it starts to fail, your engine may run rough, have trouble starting, or not start at all.
When determining if your Nissan Altima’s fuel pump is going bad, there are a few common symptoms to look out for. Here, we’ll discuss three key indicators that your fuel pump might be failing.
The sound clip above is a fuel pump priming. After it has primed, you may hear a high-pitched whining noise, which can indicate a fuel pump that is failing.
Another telltale sign that the Toyoat Altima’s fuel pump is going out is stalling, often followed by the engine restarting after several minutes. This is due to low fuel pressure.
If you find your car struggling to start or losing power, this could also indicate a fuel pump problem. Long cranking times and the Altima running irregularly are other possible indicators of a failing fuel pump.
By being attentive and catching these issues early on, you can address them appropriately and keep your vehicle running smoothly.
If your fuel pump is not functioning correctly, you may notice your engine sputtering at high speeds. This happens because the fuel pump is unable to provide a consistent flow of fuel to the engine.
If your Nissan Altima is experiencing engine sputtering or cutting out for brief periods, this could be a sign of a bad fuel pump.
Another common symptom of a failing fuel pump is a sudden loss of power when you try to accelerate. A properly functioning fuel pump should be able to deliver the required amount of fuel to the Nissan Altima’s engine when you step on the gas pedal.
If the fuel pump is failing, it might not be able to keep up with the engine’s demands, causing a noticeable drop in power as you try to accelerate. This power loss is usually temporary but can become more severe as the fuel pump deteriorates.
A bad fuel pump can also cause your car to have difficulty starting or not start at all. If your Nissan Altima struggles to start or dies immediately after starting, ensure you can hear the fuel pump turning on when you first turn the key to the “ON” position.
As mentioned above, a functioning fuel pump will typically make an audible buzzing sound as it primes the fuel lines. If you don’t hear this sound, it could be an indication of a bad fuel pump.
By keeping an eye out for these symptoms, you can quickly identify a potentially failing fuel pump and get it checked or replaced before it causes further issues with your vehicle.
The engine will still crank fine if the starter isn’t engaging; that has nothing to do with the fuel pump.
A worn fuel pump is likely the reason your Altima is experiencing the symptoms associated with low fuel pressure.
Over time, the internal components of your fuel pump wear out, causing it to become less efficient at delivering fuel to your engine. The resultant low fuel pressure can cause those symptoms, such as:
Another potential cause for bad fuel pump symptoms is a faulty fuel pump relay. This relay controls the power supply to your Altima’s fuel pump, and a faulty relay may lead to:
The fuel pump relay will usually not fail when driving. If your Altima isn’t starting, and the fuel pump relay isn’t activating, there won’t be any voltage where the fuel pump harness connects to the fuel pump.
You can test the voltage anywhere after the relay to see if power is getting through.
Lastly, a clogged fuel filter can contribute to the bad fuel pump symptoms you may experience. A fuel filter’s primary function is to remove dirt, debris, and contaminants from the fuel before it reaches your engine. A clogged filter can:
Regularly checking and replacing your fuel filter as specified in your vehicle’s maintenance guidelines is essential to maintaining optimal engine performance and avoiding bad fuel pump symptoms.
If you suspect that your vehicle has a bad fuel pump, it’s essential to get it checked by a professional mechanic, or take a look at it at home if you’re so inclined. They can perform diagnostic testing to confirm your suspicions and identify the root cause of the problem. Diagnostic testing typically involves:
By conducting these tests, you or a mechanic can determine if your fuel pump is indeed the issue or if another factor is contributing to your vehicle’s performance problems.
Should the diagnostic tests confirm that your Altima’s fuel pump is faulty, you’ll need to have it replaced as soon as possible. Here’s what’s involved in replacing a fuel pump.
Dropping a fuel tank is always easier if you siphon most of the gas out of it first.
In summary, a bad fuel pump can adversely affect your Nissan Altima’s performance and potentially lead to expensive repairs or even dangerous driving conditions.
By being aware of the common symptoms, you can take proactive steps to address the issue before it escalates. Among the key indicators to watch for are:
The good news is no matter how old your Altima is, the symptoms of a bad fuel filter are universal. It doesn’t matter if it’s in-tank or in-line. And fuel filters are cheap.
A fuel filter plays a crucial role in your Nissan Altima’s performance and longevity. As an essential component of the fuel system, its primary function is to filter out any particles that may be present in the fuel.
These contaminants may include dirt, rust, or other debris. By keeping them from entering your vehicle’s fuel system, you are protecting critical components like fuel injectors, fuel pump, and the engine itself from damage.
Over time, the fuel filter can become clogged with these particles, causing it to lose its effectiveness. This may lead to a variety of issues, such as poor engine performance or even engine failure.
That’s why it’s imperative to regularly inspect and replace your fuel filter when necessary to ensure your Nissan Altima runs smoothly.
There are physical signs that you can feel when your Altima’s fuel filter is clogging. Before taking anything apart, check to see if your engine’s computer has any trouble codes saved in it.
The engine may throw a P0087 trouble code. This trouble code detects that the fuel rail/system pressure is too low. Any trouble codes that exist could be a clue.
Sometimes when there is low fuel pressure, you may also get an oxygen sensor related trouble code as well. The real issue with diagnosing a bad fuel filter is that it resembles many other vehicular issues in terms of symptoms.
Here are the most common symptoms of a bad fuel filter in your Nissan Altima:
If you notice that your Nissan Altima is experiencing a decrease in fuel efficiency, it could be a sign that your fuel filter is clogged.
A dirty fuel filter can restrict the flow of fuel to your engine, making it work harder and consume more gas than usual, which seems counterintuitive, but the air fuel mixture will be thrown off, so whatever gas does enter the combustion chamber will not be at the proper 14.7:1 mixture.
Another symptom of a bad fuel filter in the Nissan Altima is when your engine misses or hesitates during acceleration or while driving.
This can happen when not enough fuel is reaching the engine due to a clogged filter. When your vehicle’s engine struggles or feels sluggish, it’s worth taking a closer look at the fuel filter as a possible cause.
One of the best indicators of a clogged fuel filter is going to be that the your Altima is difficult to start. This because there’s not enough fuel pressure to properly atomize the fuel as it enters the combustion chamber.
If your car is difficult to start, a clogged fuel filter would probably not be the place to start looking, especially if you are getting no trouble code for fuel pressure or the oxygen sensors.
Instead, we’d recommend taking a look at the ignition system first. Often it’ll be bad spark plugs, or a bad coil pack.
If the fuel filter has become so contaminated that the minimum amount of fuel has not been let through it, the engine won’t start at all.
At the most basic of levels your Nissan Altima needs three things to start: Air, fuel, and spark. If any of these things aren’t present, the engine won’t turn over at all.
If there’s been zero warning that the fuel filter could be going bad (hesitation, difficulty starting, etc) than a clogged fuel filter might not be the place to start. It could certainly cause the problem though.
Here’s a great video on using your eyes to diagnose the fuel filter:
A bad fuel filter in your Nissan Altima can lead to several problems, which we will discuss in this section. Keeping an eye on these issues can help you diagnose the problem early on and possibly prevent further damage.
A clogged fuel filter causes increased pressure on the fuel pump, making it work harder than necessary. As the fuel pump struggles to push fuel through the restrictive filter, it can become strained, and eventually wear out or fail.
Moreover, the decreased fuel flow may cause your vehicle to stall or lose power, especially when driving at high speeds. To avoid potential damage, be sure to address any issues with your fuel filter promptly.
Another significant issue caused by a bad fuel filter is corrosion within the fuel system. Over time, debris and contaminants in the fuel can accumulate and cause rust or other forms of corrosion.
This corrosion may lead to leaks or blockages in the fuel lines, injectors, or other components, affecting the overall performance of your vehicle.
Keeping the fuel system clean with a properly-functioning fuel filter will help protect against corrosion and ensure that your Altima performs optimally.
Before starting the process of replacing the fuel filter on your Nissan Altima, ensure that you have the following tools:
A fuel pump that is going out is going to feel the same as a bad fuel filter. This makes telling if you have a bad fuel pump vs bad fuel filter very challenging.
How do you tell them apart? A clogged fuel filter will have high pressure on its input side and low pressure on its output side. They are both going to cause the same hesitation at high speed and difficulty starting. The only way to truly tell is to place a fuel pressure gauge on both sides of the line and get a reading from both.
If your Altima isn’t starting at all, and you hear the fuel pump prime that is usually a good indication that the pump is working to some capacity. Testing your Altima’s fuel pressure on each side of the pump would be the best way to diagnose this problem.
A priming fuel pump sounds like a high-pitched whine for a few seconds and can be heard with a sharp engine right after the ignition key is turned, but before the starter is engaged.
Taking a few preventive measures can help you avoid a bad fuel filter in your Nissan Altima. These steps include regular maintenance, filling up at reputable gas stations, and using fuel additives when necessary.
Following these guidelines can extend the life of your fuel filter and keep your engine running efficiently.
To ensure the health of your fuel filter, regular maintenance is essential. You should perform routine checks and change your fuel filter as recommended in your Nissan Altima owner’s manual.
Filling up at reputable gas stations can also prevent bad fuel filter issues. Reputable gas stations maintain high quality standards and proper filtration systems for their fuel, minimizing contaminants and debris that can damage or clog your fuel filter.
By sticking to well-established and reputable gas stations, you’re less likely to encounter potential fuel filter problems down the line.
The occasional use of fuel additives can help clean and maintain your fuel filter. Fuel additives contain special chemicals that dissolve deposits, prevent corrosion, and improve fuel combustion.
Make sure to choose additives that are compatible with your Altima’s specific engine type and follow the manufacturer’s instructions for use. Be cautious not to overuse fuel additives, as excessive use can have adverse effects on your engine.
By implementing these preventive measures, you can protect your Nissan Altima’s fuel filter and keep your vehicle running smoothly.
The symptoms of a bad fuel pump match a lot of other common problems that can occur in the Nissan Altima. Testing the filter and pressure on each side of it are going to be the quickest ways to rule it out. If there is anything you would like to add, please leave a comment below. Good luck!
A MAF sensor measures the density of the air entering the intake manifold. It passes this information onto your Altima’s ECU. The ECU uses this information along with other sensor data to control the amount of fuel that enters the combustion chamber.
If you do determine that you need a new mass airflow sensor, they aren’t too expensive. And, most of the time they are right by the air box and easy to replace.
When the mass airflow sensor has gone bad, you’ll definitely feel it. Here are the most common symptoms of a bad or failing MAF sensor:
If the MAF sensor has gone bad, it’ll trigger the check engine light and provide an OBDII trouble code. This is great because it helps you narrow down the problem. The two most common trouble codes in relation to the MAF sensor are:
There are other codes related to the mass air flow sensor as well, but these are the most common ones. Here’s a fantastic video on how to diagnose a bad MAF sensor using a multimeter from Ratchets and Wrenches on YouTube.
Often, the mass airflow sensor really only needs cleaning when they go bad. Some folks recommend using alcohol because it’s usually on hand, and can clean the sensor. This is a bad idea, it can ruin the sensor. Uses mass airflow sensor cleaner. It’s really cheap and available at any parts store. It sure beats the heck out of having to buy a new sensor.
Replacing a bad MAF sensor can make your Altima feel like a new vehicle. Good luck with the diagnosis. If there is anything that you would like to add, please feel free to leave a comment below.
Your Altima’s engine is a pump. It mixes air and fuel and needs a strong ignition of the two to run correctly. If any of these three variables are off, you will not have optimal combustion, and it can jerk while accelerating.
Start with the check engine light.
If your check engine light is on, the first thing that you should do is scan the computer system and see if there are any OBDII diagnostic trouble codes. You can pick up a scanner pretty cheap. Or, most major parts stores will provide this service to you free of charge.
Here are the most common issues that cause your Altima to jerk when accelerating:
A few things can cause an engine to misfire. More often than not, it’s going to be the spark plugs or coil packs that are the culprit. A misfire is the most common reason your Nissan Altima jerks while accelerating.
Here are some common misfire causes.
While the ignition system is the most likely reason a vehicle will jerk when accelerating, it is not the only one.
Your Nissan Altima’s exhaust system has three functions. It releases exhaust gasses behind the car, scrubs pollutants via the catalytic converter, and helps the engine adjust the air/fuel mixture via O2 sensors. All three can cause your Altima to jerk while accelerating.
Your Altima’s exhaust must pass through the catalytic converter to get to the tailpipe. It is possible for the converter to clog. This is particularly true if a rich air/fuel mixture has run through it for a while. When it is blocked, your Altima will struggle and jerk when accelerating.
You may also notice that it has a “top speed” much lower than you would need to drive on the highway. This happens when the catalytic converter is almost full and the engine is choking on its exhaust.
The oxygen sensors meter the exhaust as it exits the combustion chamber. If one is faulty, it can change the air-fuel ratio to the point that your Altima starts jerking.
Have you driven your car over something that scraped the bottom hard? Your Altima’s exhaust pipe may have gotten pinched. When pinched, exhaust gasses can’t escape, and you’ll feel a jerking sensation (or a lack of power).
Modern vehicles use crank and cam sensors to fire the spark plugs at the perfect time. There are two ways that your Nissan Altima’s engine can be out of time. A crank or cam sensor is having an issue, or the timing chain has jumped a tooth.
You should hear slapping under the timing cover if the timing chain has jumped a tooth. If a crank or cam sensor is not reading the timing position correctly, it can cause your Altima to jerk.
Here’s how to replace the crank sensor on an older Altima, which is a very common reason they jerk when accelerating.
Your Altima needs fuel to run. If one of your fuel injectors is clogged or not firing correctly, it can cause a jerking sensation.
Outside of bad fuel injectors, a bad fuel pump or fuel filter can also cause a jerk while accelerating. When either of these goes bad, there is insufficient fuel pressure at the fuel rails. The best way to determine if there’s a lack of fuel is to test the fuel pressure at the rails.
You should check if the air intake is blocked with something foreign. Or if you have a filthy air filter. Not enough air will also throw off the air-fuel ratio and make the Altima jerk.
Checking your air filter only takes a second.
The motor and transmission mounts connect your Altima’s engine and transmission to the chassis. If one breaks, it can lead to jerking when braking, accelerating or putting the vehicle in gear.
Good luck figuring out what is causing your Nissan Altima to jerk while accelerating. Everything described above should cause the check engine light to come on, with the exception of a bad motor/transmission mount. So, make sure you get the trouble codes and take it from there.
If you’ve found oil on your spark plug, it is a cause for concern. It doesn’t necessarily indicate a disaster. Oil on the plugs is usually caused by a bad valve cover gasket or O-Ring (overhead cam engines). There are other causes as well.
Any gas engine needs three things in order to achieve ignition. It needs air, fuel, and spark. When it doesn’t get the optimal proportion of all three, it is not perform well.
The ignition system takes care of the spark part of the equation. The spark plugs are the final stop in the ignition system’s process. An oily spark plug can cause the spark part of the equation to be seriously compromised.
If you do end up with oil on your spark plugs, you’re going to need to consider replacing them.
When there is oil on the spark plug, it’s going to make combustion in its cylinder less efficient.
Most of the time, oil on your spark plugs is going to be caused by a bad O-ring seal on the plug itself or a bad valve cover gasket. Here are the most common symptoms of oil on spark plugs:
Bad Valve Cover Gasket– Oil is pumped from the oil pan up through the cylinder heads. The valve cover gaskets seal the valve covers, which are on top of the head. They are there for you to have access to the head. As they age, they can dry out and go bad. When this happens oil can leak out of the engine and into the spark plug wells.
Valve Guides– As an engine wears throughout its life, the valve guides can go bad. When this happens, oil can get directly into the combustion chamber. While, the combustion process can burn off a lot of this oil, eventually it’ll hurt the plug and it’ll get oily.
O-Ring– On most overhead cam designs, there is an O-Ring that protects the spark plug from oil from above. If this ring dries out or fails over time, it will begin to allow oil to drip onto the plug.
Piston Rings– Piston rings surround your piston and fill the already tiny space between the piston and the cylinder wall. This keeps oil from entering the combustion chamber. If these rings begin to fail, it can lead to oil on the spark plugs.
Bad Piston– If the piston runs too long hot, it can develop a crack. This crack will let oil through. When this is the case, oil on the spark plugs is almost never the only indication of the problem. There is should also be a lack of engine power and some truly horrible knocking sounds.
Oil on the spark plug threads is typically caused by a leak from the valve cover gaskets onto the plugs themselves.
Getting oil on the spark plugs is always a sign of a problem with something other than the plug itself. Although, enough oil can ruin a plug anyway. Good luck diagnosing your issue. Please feel free to leave a comment if there is anything that you would like to add.
There will always be trouble codes associated with the Nissan Altima’s check engine light flashing. The first thing you want to do is look them up with an OBD II scanner.
A code scanner is cheap. Use it to discover exactly why your car’s computer flashed this light. Also, most parts stores will scan your vehicle for free if your check engine light is on.
A misfire is the number one reason your Altima’s check engine light will flash.
Your car’s ignition system consists of spark plugs, plug wires, and ignition coil packs (older vehicles have a distributor that has the same function as coil packs). These parts work in concert to ignite the fuel in the combustion chamber at just the right time.
P0300 indicates that your Altima’s engine is misfiring, but it can’t detect which cylinder it’s coming from. This code is often thrown when there is a fuel issue, a timing issue, and not just bad ignition components (most likely).
If the only code your car has is for a cylinder-specific misfire. Start with pulling the plug and taking a look at it.
These trouble codes correspond with a specific cylinder misfiring (cylinder number corresponds with its place in the firing order). For example, P0301 indicates the Nissan Altima is misfiring in cylinder 1.
Although it’s a bad sign when the service engine soon light flashes, when one of these codes comes up with it (and nothing else), it’s almost always one spark plug or ignition coil. A leaking fuel injector can also cause a cylinder-specific misfire code.
There are other misfire-related codes as well, but those are the most common ones.
Keeping in mind that any engine needs air, fuel, and spark for ignition, your Nissan Altima’s fuel system can often cause the engine to misfire. It can run too lean or rich. Alternatively, there could be too much.
While a majority of the time, the flashing check engine light is going to be caused by a misfire related to your Altima’s ignition system or fuel system (as stated above), other issues can cause it.
Do not drive your Nissan Altima with a flashing check engine light.
When your engine is misfiring, it dumps raw fuel into the exhaust. This raw fuel can detonate, which causes damage to the catalytic converter and the exhaust system itself.
A flashing check engine light means you should not drive your Nissan Altima until you’ve fixed the engine.
If your Altima is shaking and the check engine light is flashing, it’s likely one or more of your car’s cylinders is misfiring.
We recommend that you don’t drive, if at all possible, until you diagnose and fix your Altima’s flashing check engine light.
Just pretend that it’s letting you know that it will cost you way more money to fix the problem if you keep driving it.
The good news is that the check engine light indicates that there are Diagnostic Trouble Codes (DTCs) stored in your Altima’s computer, which is a very good thing. DTC’s really help save time determining what is wrong with your car.
The check engine light is often referred to as the Malfunction Indicator Lamp (MIL) or Service Engine Soon light. All three terms are 100% interchangeable.
Trouble codes are a number sequence of letters and numbers that correspond with a standardized list of problems that can occur in any vehicle, including the Nissan Altima. Some of them are Nissan specific, while most have the same meaning no matter who made the vehicle.
The most common of all trouble codes is P0420 (it indicates your Nissan Altima’s catalytic converter isn’t scrubbing pollutants efficiently).
Here are some of the other most common codes:
The most common codes are related to the emissions system. Some of them are as easy to fix as replacing your Altima’s. Others require serious diagnostic tests from a repair shop.
You can either pull the trouble codes from your Altima’s PCM (Powertrain Control Module) yourself, or you can bring your vehicle to a parts store or shop to have it scanned.
You can put a scan tool into the OBD II port and pull codes out of the diagnostic system yourself. Any vehicle made for the 1996 model year and up uses the same protocol.
You can usually find the OBD II port underneath the Altima’s steering wheel. The exact location of the port is going to depend on what model year you have. If you don’t see it check the owner’s manual or do a quick google image search.
Once your scanner is online, you can pull the codes. You should see a retrieve codes option.
If you don’t have a scan tool, you can take your Altima to the local parts store. Most of them are happy to pull the codes for you for free.
A lot of auto shops also offer free scan service, but you may find pressured into authorizing whatever repairs they suggest on the spot.
Once you have the codes in hand, you can look them up and determine what’s wrong with your Altima.
There are three ways to reset the Nissan Altima’s check engine light. We recommend trying to identify the problem and fixing it before resetting the check engine light.
The best way to clear the check engine light is to pull the trouble code, identify and fix the issue and then drive your Altima around until the module that threw the code recognizes that the problem is fixed.
Sometimes it can take a few drive cycles for your car’s check engine light to shut down. Other times, it’ll happen as soon as you fire the vehicle up. Some folks prefer to clear the code and see if it comes back on
You can use an OBDII scanner to turn off your Altima’s check engine light. The catch is, that if you don’t fix the problem, the light will turn on again.
This is done by connecting a scan tool to your Altima’s PCM and choosing the “clear codes” option.
Once you’ve identified and fixed the issue, wait for three or four days of normal driving to see if the Check Engine Light turns back on.
If it does not come back on after this period, then you can assume that your Nissan Altima is fixed and the light won’t be turning back on.
If you’ve identified and fixed the issue that caused your Altima’s Check Engine Light to come on, resetting the light is as simple as disconnecting and reconnecting the battery. This can be done by unhooking both cables from the battery terminals (negative cable first) and waiting 30 seconds before reconnecting them.
Once the battery is reconnected, your Check Engine Light should be reset and should no longer be illuminated. If the light does come back on again after you reset it, then it means that the issue has not been properly fixed and needs further attention.
If you are looking to get your Nissan Altima through emissions and the check engine light is on, it is an automatic fail in almost every State in the Union. It doesn’t matter why the check engine light is on, it only matters that a code is stored.
Here’s a list of the emissions regulations of each State.
You can’t reset a check engine light to circumvent emissions requirements. When you reconnect the battery, the OBD II system is going to need several drive cycles to qualify to take an emissions test, which will give it enough time to recognize the issue.
Whether you can drive your Altima with the check engine light on depends on the code(s) that triggered the check engine light.
You certainly can’t drive the Nissan Altima with the check engine light flashing. A flashing check engine light indicates that there is a serious problem with the engine.
A flashing Check Engine Light typically indicates a serious issue with your Altima and should not be ignored. It usually indicates a catastrophic misfire that can dump raw fuel into the exhaust system, which can damage the catalytic converter and cause backfiring. Do not drive your car with a flashing check engine light.
P0304 is a drivability concern and should be dealt with right away. If it’s bad enough to cause your Altima’s check engine light to flash, avoid driving your car altogether until you find the misfire and repair your engine.
Repairing P0304 should be considered a high priority. Unlike a lot of the OBDII codes, this code has to do directly with engine combustion, and driving with a misfiring engine can damage your Altima’s catalytic converter.
P0304 is a cylinder-specific misfire code, meaning only your Altima’s fourth cylinder has a misfire.
Before you can even diagnose P0304 in your car, you need to find the fourth cylinder’s location.
On “V” configuration engines, it’ll usually be the second cylinder on the head further away from the front of the engine. On inline engines, the fourth cylinder will usually be the fourth in from the engine accessories.
A quick Google image search will confirm the correct cylinder (include your Altima’s model year and engine type), or they can print it up for you at most parts counters.
In order for an engine to burn fuel efficiently, each cylinder needs the following:
If one of the above variables is off, your Altima’s fourth cylinder will misfire, or it won’t fire at all.
Here are the most common symptoms of P0304 in the Nissan Altima. There may be no noticeable symptoms at all.
Here are the most common P0304 Nissan Altima causes; they are presented somewhat in order from most to least likely to be causing the code in your car:
If P0304 is the only code you get when you plug an OBD II scanner into your Altima, this section should help you determine what is causing the code.
If you have multiple codes with P0304, jump down a section.
Here’s a quick and easy test to determine what is causing your Altima’s fourth cylinder to misfire. Swap ignition parts to another cylinder. Here’s how to do it.
Here’s what to look for when the swap test didn’t change your car’s misfire code number.
The most likely reason your Altima will get P0300 and P0304 simultaneously is faulty spark plugs.
P0300 in the Nissan Altima indicates random multiple misfiring, which means that multiple cylinders are misfiring at the same time.
If your Nissan Altima has P0300 and P0304 error codes, it’s best to diagnose why the fourth cylinder is misfiring and see if that will fix the P0304 code.
Try doing the swap test from the previous section. Make note of the condition of BOTH spark plugs as you swap them. If they look fouled, new plugs will likely clear this code.
Look for a vacuum leak around the fourth cylinder or a bad fuel injector.
While there are many potential causes for P0171, the most prevalent is a vacuum leak.
When your Altima has P0304 and P0171 together, it’s often caused by a clogged or underperforming fuel injector. Look for a vacuum leak at the intake around cylinder four.
Treat P0304 with these codes like it has P0300.
P0304 will often be accompanied by codes P0301, P0302, P0303, P0305, etc… These codes indicate a misfire in cylinders one, three, four, and five, respectively.
Treat P0304 with these codes like it has P0300. Suspect an ignition-related cause or a vacuum leak.
P0304 is cause for concern and, left unfixed, can leave you stranded. Your Altima will be virtually undrivable if the fourth cylinder stops firing altogether. The raw fuel can also damage the catalytic converter.
We do not advise driving your Altima with P0304. It can cause damage to your car, particularly if the check engine light is flashing.
Is P0304 hard to repair?
Most of the time, P0304 is not hard to repair, as you’ll be swapping out ignition parts. It’s a great first-time project for a shade tree mechanic. If the problem ends up not being ignition related, that’s when you might have to bring it into a shop.
Replacing the spark plug or coil packs is the most common fix for P0304 in the Nissan Altima. There are other causes, but the swap test can help narrow them down considerably.
P0303 is a real drivability concern and should be dealt with right away. If it’s bad enough to cause your Altima’s check engine light to flash, avoid driving your car altogether until you find the misfire and repair your engine.
Repairing P0303 should be considered a high priority. Unlike a lot of the OBDII codes, this code has to do directly with engine combustion. It also can cost money to ignore it, since driving with a misfire can damage the Altima’s catalytic converter.
P0303 is a cylinder-specific misfire code, meaning it’s only the third cylinder that has a misfire. Before you can diagnose P0303 in your car, you need to find the third cylinder.
On “V” configuration engines, it’ll usually be the second cylinder on the head closer to the front of the engine. On inline engines, the third cylinder will usually be the three in from the engine accessories.
A quick google image search will confirm the correct cylinder (include your Altima’s model year and engine type).
Most parts stores will print you a copy of your engine’s cylinder numbers and their location on a sheet of register paper.
In order for an engine to burn fuel efficiently, each cylinder needs the following:
If one of the above variables is off, your Altima’s third cylinder will misfire, or it won’t fire at all.
Here are the most common symptoms of P0303 in the Nissan Altima. There may be no noticeable symptoms at all.
Here are the most common P0303 Nissan Altima causes; they are presented somewhat in order from most to least likely to be causing the code in your car:
If P0303 is the only code you get when you plug an OBD II scanner into your Altima, this section should help you determine what is causing the code.
If you have multiple codes with P0303, jump down a section.
Here’s a quick and easy test to determine what is causing your Altima’s third cylinder to misfire. Swap ignition parts to another cylinder. Here’s how to do it.
Here’s what to look for when the swap test didn’t change your car’s misfire code number.
The most likely reason your Altima will get P0300 and P0303 simultaneously is faulty spark plugs.
P0300 in the Nissan Altima indicates random multiple misfiring, which means that multiple cylinders are misfiring at the same time.
If your Nissan Altima has P0300 and P0303 error codes, it’s best to diagnose why the third cylinder is misfiring and see if that will fix the P0303 code.
Try doing the swap test from the previous section. Make note of the condition of BOTH spark plugs as you swap them. If they look fouled, new plugs will likely clear this code.
Look for a vacuum leak around the third cylinder or a bad fuel injector.
While there are many potential causes for P0171, the most prevalent is a vacuum leak.
When your Altima has P0303 and P0171 together, it’s often caused by a clogged or underperforming fuel injector. Look for a vacuum leak at the intake around the third cylinder.
Treat P0303 with these codes like it has P0300.
P0303 will often be accompanied by codes P0301, P0302, P0304, P0305, etc… These codes indicate a misfire in cylinders one, three, four, and five, respectively.
Treat P0303 with these codes like it has P0300. Suspect an ignition-related cause or a vacuum leak.
P0303 is cause for concern and, left unfixed, can leave you stranded. Your Altima will be virtually undrivable if the third cylinder stops firing altogether. The raw fuel can also damage the catalytic converter.
We do not advise driving your Altima with P0303. It can cause damage to your car, particularly if the check engine light is flashing.
Most of the time, P0303 is not hard to repair, as you’ll be swapping out ignition parts. It’s a great first-time project for a shade tree mechanic. If the problem ends up not being ignition related, that’s when you might have to bring it into a shop.
Replacing the spark plug or coil packs is the most common fix for P0303 in the Nissan Altima. There are other causes, but the swap test can help narrow them down considerably.
P0302 is a real drivability concern and should be dealt with right away. If it’s bad enough to cause your Altima’s check engine light to come on, you shouldn’t drive your car at all.
Repairing P0302 should be considered a high priority. Unlike a lot of the OBDII codes, this code has to do directly with engine combustion. It also can cost money to ignore it, since driving with a misfire can damage the Altima’s catalytic converter.
P0302 is a cylinder-specific misfire code, meaning it’s only the second cylinder that has a misfire. But, where is the second cylinder?
On “V” configuration engines, it’ll usually be the first cylinder on the head further back from the front of the engine. A quick google image search will confirm the correct cylinder (include your Altima’s model year and engine type).
In order for an engine to burn fuel efficiently, each cylinder needs:
If one of the above variables is off, your Altima’s second cylinder will misfire, or it won’t fire at all.
Here are the most common symptoms of P0302 in the Nissan Altima.
There are quite a few things that can cause the P0302 trouble code to trigger in the Nissan Altima.
Here are the most common problems that may cause misfiring. They are presented somewhat in order from most to least likely to be causing P0302:
If P0302 is the only code you get when you plug an OBD II scanner into your Altima, this section should help you determine what is causing the code.
If you have multiple codes with P0302, jump down a section.
Here’s a quick and easy test to determine what is causing your Altima’s second cylinder to misfire. Swap ignition parts to another cylinder. Here’s how to do it.
Here’s what to look for when the swap test didn’t change your car’s misfire code number.
The most likely reason your Altima will get P0300 and P0302 simultaneously is faulty spark plugs.
P0300 in the Nissan Altima indicates random multiple misfiring, which means that multiple cylinders are misfiring at the same time.
If your Nissan Altima has P0300 and P0302 error codes, it’s best to diagnose why the second cylinder is misfiring and see if that will fix the P0302 code.
Try doing the swap test from the previous section. Make note of the condition of BOTH spark plugs as you swap them. If they look fouled, new plugs will likely clear this code.
Look for a vacuum leak around the second cylinder or a bad fuel injector.
P0171 is one of the most common trouble codes there is. While there are many potential causes for P0171, the most prevalent is a vacuum leak.
When your Altima has P0302 and P0171 together, it’s often caused by a clogged or underperforming fuel injector.
Treat P0302 with these codes like it has P0300.
P0302 will often be accompanied by codes P0301, P0303, P0304, P0305, etc… These codes indicate a misfire in cylinders one, three, four, and five, respectively.
Treat P0302 with these codes like it has P0300. Suspect an ignition-related cause or a vacuum leak.
P0302 is cause for concern and, left unfixed, can leave you stranded. Your Altima will be virtually undrivable if the second cylinder stops firing altogether. The raw fuel can also damage the catalytic converter.
We do not advise driving your Altima with P0302. It can cause damage to your car.
Most of the time, P0302 is not hard to repair, as you’ll be swapping out ignition parts. It’s a great first-time project for a shade tree mechanic. If the problem ends up not being ignition related, that’s when you might have to bring it into a shop.
Replacing the spark plug or coil packs is the most common fix for P0302 in the Nissan Altima. There are other causes, but the swap test can help narrow them down considerably.
P0300 is often accompanied by cylinder-specific misfire codes (P030X, where the X indicates the cylinder number that is misfiring). If you have P0300 and a cylinder-specific misfire, the cylinder indicated by the specific codes would be where to start looking for your problem.
Definition: P0300: Random Multiple Misfire Detected.
Symptoms: Rough idle, jerks when accelerating, decreased MPG.
Common Causes: Ignition components or it’s a symptom of another problem.
Breakdown Risk? Yes.
Repair Cost (Parts): Typically less than $250 for the common issues.
Repair Difficulty: Easy, if it’s ignition related.
P0300 is a general diagnostic trouble code. Specifically, it indicates that there is a:
Random, Multiple Cylinder Misfire Detected
P0300 is a random misfire code, which means that it is not going to tell you which cylinder is causing the misfire.
Since something is causing cylinders to misfire randomly, figuring out the cause is less cut and dry than a cylinder-specific misfire code. This code can indicate an issue with the ignition system, but it is often a symptom of another problem.
How you approach P0300 depends on if there were any other codes present.
There are almost always noticeable symptoms associated with P0300 other than the check engine light.
If your Altima’s engine is misfiring enough to damage the catalytic converter, the check engine light may flash on and off as a warning to stop running the engine until you can fix it.
When diagnosing the cause of P0300 in your Nissan Altima the problem can be broken down into two main categories.
Important to pull and weigh all the codes together. The misfiring could just be a symptom of the real problem.
For example, if you got a fuel pressure-related code, that indicates your Altima’s fuel rail isn’t getting enough fuel pressure for the fuel injectors to work properly, which would cause a random misfire.
Start here if your Altima has only misfire/ignition-related codes.
The most likely cause of P0300 in most vehicles is a bad ignition component (particularly the spark plugs).
While most modern vehicles use iridium spark plugs that can last a long time, they still should be changed at Nissan’s recommended maintenance intervals.
If your Altima has a few cylinder-specific trouble codes, it may be a good idea to check and see if there is any wiring damage around the wiring harness connecting the PCM to the coil packs.
Here’s how to test a coil pack, how to tell if a spark plug is bad (video), and how to test plug wires (video).
If your Altima’s fuel pressure is low, you may also encounter P0171 (fuel trim lean) or P0087 (fuel rail pressure too low).
If there isn’t enough fuel getting to the engine, it will keep leaning out the air-fuel mixture.
If your car’s fuel pressure is really low, it’ll cause noticeable misfiring as there won’t be enough fuel pressure to atomize the gasoline as it enters the combustion chamber.
Typically, if your Altima has low fuel pressure, it’ll act fine when it doesn’t need a lot of fuel. But it’ll sputter and act like it will die at speed or under heavy acceleration.
As the fuel pressure decreases, it’ll start happening when you give it less and less gas. Or, your Altima will shut down when driving but then turn back on.
It’s really easy to check the fuel pressure at the rail. Autozone or any other parts store will usually have a loaner fuel pressure testing kit.
The two most prevalent causes of low fuel pressure are an issue with the fuel pump or fuel regulation.
Here’s some information on how to tell if you have a bad fuel filter. Here’s how to test fuel pressure with a fuel pressure tester.
P0171 is the most common code to see with a vacuum leak
If your Altima has a vacuum leak, unmetered air is entering the combustion chamber, which usually leans out the air-fuel mixture.
A lean air/fuel ratio will cause the cylinders to misfire, and it’ll throw the P0300.
Since a vacuum leak almost always affects each cylinder the same, you’ll typically get P0300 with it and not any cylinder-specific misfire codes.
Here’s a great article from Popular Mechanics on how to detect a vacuum leak. Chasing one down is pretty easy. Popular Mechanics: How to find a vacuum leak.
Most mechanical issues won’t throw other codes.
Mechanical issues can cause misfiring. Here are the most common mechanical issues that can cause P0300:
Old gas can cause misfiring.
If your misfire started a minute or two after filling up, it could be that your Altima has some bad gas. The same goes if it’s been sitting for over 90 days.
P0300 will often be fixed by something obvious. When it’s not glaringly obvious what is wrong, a tune-up is a great place to start. Here’s a good order to approach fixing P0300 in the Nissan Altima.
P0300 is cause for concern, and left unfixed can get worse. Left ignored, a misfire will eventually get bad enough that your Altima may not start.
Yes. A clogged converter will increase backpressure. An engine is a pump. When there’s too much backpressure, air can’t quickly move through the combustion chambers and will misfire.
You can use an OBD II scanner to clear P0300 in the Nissan Altima. You have to fix the root cause of P0300 in your car. Otherwise, when you clear the code, it’ll come right back.
P0301 is a fairly common trouble code with the Nissan Altima. It’s an OBD2 code and indicates that your car’s first cylinder is misfiring.
P0301 is certainly a cause for concern and should be considered a threat to the drivability of your Altima.
Fixing P0301 should be considered a high priority. Unlike a lot of the OBDII codes, this code has to do directly with engine combustion. It also can cost money to ignore it, since driving with a misfire can damage the Altima’s catalytic converter.
P0301 is a cylinder-specific misfire code, meaning it’s only the first cylinder that has a misfire. Cylinder one is typically the closest to the front of the engine.
On “V” configuration engines, it’ll usually be the first cylinder on the head closest to the front of the engine. A quick google image search will confirm the correct cylinder (include your Altima’s model year).
In order for an engine to burn fuel efficiently, each cylinder needs:
If one of the above variables is off, your Altima’s first cylinder will misfire, or it won’t fire at all.
Here are the most common symptoms of P0301 in the Nissan Altima.
There are quite a few things that can cause the P0301 trouble code to trigger the Nissan Altima.
Here are the most common problems that may cause it. They are presented somewhat in order from most to least likely to be causing the code:
If P0301 is the only code you get when you plug an OBD II scanner into your Altima, this section should help you determine what is causing the code.
If you have multiple codes with P0301, jump down a section.
There’s a quick and easy test to determine what is causing your Altima’s cylinder one to misfire. Swap ignition parts to another cylinder. Here’s how to do it.
Here’s what to look for when the swap test didn’t change your car’s misfire code number.
The most likely reason your Altima will get P0300 and P0301 simultaneously is faulty spark plugs.
P0300 indicates random multiple misfiring, which means that multiple cylinders are misfiring at the same time.
If your Nissan Altima has P0300 and P0301 error codes, it’s best to diagnose why cylinder one is misfiring and see if that will fix the P0301 code.
Try doing the swap test from the previous section. Make note of the condition of BOTH spark plugs as you swap them. If they look fouled, new plugs will likely clear this code.
Look for a vacuum leak around the first cylinder or a bad fuel injector.
P0171 is one of the most common trouble codes there is. While there are many potential causes for P0171, the most prevalent is a vacuum leak.
When your Altima has P0301 and P0171 together, it’s often caused by a clogged or underperforming fuel injector.
Treat P0301 with these codes like it has P0300.
P0301 will often be accompanied by codes P0302, P0303, P0304, P0305, etc… These codes indicate a misfire in cylinders two, three, four, and five, respectively.
Treat P0301 with these codes like it has P0300. Suspect an ignition-related cause or a vacuum leak.
P0301 is cause for concern and, left unfixed, can leave you stranded. Your Altima will be virtually undrivable if the first cylinder stops firing altogether. The raw fuel can also damage the catalytic converter.
We do not advise driving your Altima with P0301. It can cause damage to your car.
Most of the time, P0301 is not hard to repair, as you’ll be swapping out ignition parts. It’s a great first-time project for a shade tree mechanic. If the problem ends up not being ignition related, that’s when you might have to bring it into a shop.
Replacing the spark plugs is the most common fix for P0301 in the Nissan Altima. There are other causes, but the swap test can help narrow them down considerably.
If you’ve found oil on your Nissan Altima’s spark plug, it should be a cause for concern. It doesn’t necessarily indicate a major engine problem. When there is oil on the spark plugs is usually caused by a bad valve cover gasket or O-Ring (overhead cam engines). There can be other causes as well.
Any gas engine needs three things in order to achieve combustion. It needs air, fuel, and spark. When any of these three necessary elements is off, your Altima’s engine will not perform as it should.
The ignition system takes care of the spark part of the combustion equation. The spark plugs are the final stop in the ignition system’s process. An oily spark plug can cause the spark plug to not fire properly.
If you do end up with oil on your spark plugs, you’re going to need to consider replacing them.
When there is oil on the spark plug, it’s going to make combustion in its respective cylinder less efficient. Here are the most common symptoms of an oily plug:
Most of the time, oil on your spark plugs is going to be caused by a bad O-ring seal on the plug itself or a bad valve cover gasket. Here are the most common symptoms of oil on spark plugs:
Bad Valve Cover Gasket– Oil is pumped from the oil pan up through your Altima’s cylinder heads. The valve cover gaskets seal the valve covers, which are on top of the head. They are there for you to have access to the head. As they age, they can dry out and go bad. When this happens oil can leak out of the engine and into the spark plug wells.
Valve Guides– As an engine wears throughout its life, the valve guides can go bad. When this happens, oil can get directly into the combustion chamber. While, the combustion process can burn off a lot of this oil, eventually it’ll hurt the plug and it’ll get oily.
O-Ring– On most overhead cam designs, there is an O-Ring that protects the spark plug from oil from above. If this ring dries out or fails over time, it will begin to allow oil to drip onto the plug.
Piston Rings– Piston rings surround your piston and fill the already tiny space between the piston and the cylinder wall. This keeps oil from entering the combustion chamber. If these rings begin to fail, it can lead to oil on the spark plugs.
Bad Piston– If the piston runs too long hot, it can develop a crack. This crack will let oil through. When this is the case, oil on the spark plugs is almost never the only indication of the problem. There is should also be a lack of engine power and some truly horrible knocking sounds.
Getting oil on the spark plugs is always a sign of a problem with something other than the plug itself. Although, enough oil can ruin a plug anyway. Good luck diagnosing your Altima. Please feel free to leave a comment if there is anything that you would like to add.
An engine functions as a pump, requiring a precise combination of fuel, air, and spark. If any element of this trio is imbalanced, your Nissan Altima won’t run right (or at all).
While a misfire is the symptom of bad spark plugs, bad spark plugs almost always indicate a problem with the engine (more on that in section 2).
The fundamental design and function of spark plugs have remained broadly consistent over the past century. In the Nissan Altima, they are positioned atop the combustion chamber and ignite the air-fuel mixture, initiating the engine’s power stroke.
Something that has changed about modern spark plugs is that many of them use iridium, don’t need to be gapped, and can last for 100k miles with little issue.
That being said, they still can go bad. The good news is that if you do need to replace your Altima’s plugs, they are very affordable.
There are a lot of potential symptoms related to foul spark plugs in your Altima. We always recommend using an OBDII scanner to pull your trouble codes if you have a check engine light on. It can really narrow your search down. If you don’t have one, your local parts store will do this for you for free.
It is also worth noting that the symptoms of bad spark plugs in your car will be almost the same as any other bad part in the ignition process. Bad coil packs will produce the same results and feel like bad plugs.
The check engine light is one of the most common symptoms of bad spark plugs. More often than not, your Altima’s computer can detect bad spark plugs in your car.
There are several misfire-related trouble codes.
As you ask your Altima for more power, the fuel and ignition systems respond. If acceleration has diminished, it should be felt. The fewer cylinders that your engine has, the more that one cylinder not firing correctly will have. If you have one or more bad spark plugs, it’ll cause the acceleration of the Altima to be weaker.
The less efficient your engine’s combustion, the more fuel will be wasted. This leads to a decrease in fuel economy.
When you take your Altima in for a tune-up due to decreased fuel economy, checking the spark plugs (and ignition system in general) is going to be one of the very first places a mechanic will look at.
Misfiring is the most common symptom of bad spark plugs. All of the other symptoms are a result of the misfiring itself. The real question is, what is causing the misfire? There is more to your Altima’s ignition system than just the plugs. There are also coil packs and spark plug wires.
There are also non-ignition-related circumstances that can cause your Nissan Altima to misfire. That would include a lack of fuel pressure, bad fuel injectors, or even a timing chain (or belt) that has jumped. Since there are so many reasons that a vehicle can misfire, we recommend testing for trouble codes first.
When a spark plug is misfiring, it is often most pronounced at idle speed. This is because when your car’s engine turns slower, it is easier to detect. You’ll feel a rough vibration.
There are two parts to diagnosing bad spark plugs in your Altima. The first is to identify the misfiring cylinder. The second is to inspect the plug. If it looks ok, follow the diagnostic steps listed below. If it doesn’t look ok, use the chart below to determine why the plug has gone bad.
If your Altima has a cylinder-specific misfire code, you can swap parts to diagnose what’s failed. You will need an OBD II code scanner.
Here’s how:
The most common reason a modern vehicle’s spark plug wears out is the wearing down of the electrode (normal wear), followed by carbon deposits. Consult the chart below to help you determine why your Altima’s spark plug went bad.
Be aware that almost all symptoms of a bad spark plug in your Altima could also be other issues with the ignition system. Good luck diagnosing the problem. Feel free to leave a comment below if there is anything that you would like to add.
While your Nissan Altima’s engine mounts can last the life of the entire vehicle, it is possible that they will go bad. Vibration and a clunking sound are the two most noticeable symptoms when driving the vehicle. There are plenty of visible signs as well.
Engine mounts connect the engine to the frame of the Altima. They also provide vibration dampening. It is essential to the operation of the vehicle that they are working properly. If you have bad motor mounts, it’s usually pretty obvious.
The job of the motor mounts is to keep your Altima from rattling to death, while keeping the engine in the engine bay. All of the symptoms of a bad motor mount are going to be related to vibration, and the motor moving from it’s proper location. That being said, here are the three most common symptoms of a bad motor mount. They usually happen in stages.
The most noticeable symptom of a motor mount that is going bad is vibration. That is, more vibration than you would typically feel when you are driving your Altima. You’ll know when it’s happening. It may not necessarily feel like the vehicle is going to rattle apart, but it’s very noticeable.
This is the most prominent symptom of a bad engine mount, and the first one that you’ll typically notice. If it is left alone long enough, it’ll lead to hard clunking sounds, which we’ll cover next ↓.
An engine mount that has gone bad will begin to exhibit a clunking sound. This sound will be most noticeable when putting your Altima in and out of gear, when the engine shifts, as well as when you accelerate or de-accelerate abruptly.
This clunking comes from the mount being worn and having enough play to move when the force suddenly changes. This clunking may be accompanied by, or lead to full on engine movement ↓.
If you are driving and you feel the engine banging around, that’s a sure indication that a motor mount has failed. Really, you shouldn’t drive a vehicle with a motor mount clunking or even vibrating. If you hear and feel the engine rolling around, it’s time to stop driving and have the motor mounts replaced immediately. It’s going to cause all sorts of collateral damage in there.
You can inspect the motor mounts and look to see if they have any free play. If you take a look at your Altima’s engine as it goes in and out of gear, it is normal to observe some movement of the engine as it torques one way or the other. It is not normal for it to make a clunking noise, or move excessively. It is very difficult to tell that a motor mount is bad just by looking at it. That’s why it’s better to look for the signs of a bad motor mount, than to look at the mounts themselves.
Here are some ways of telling if your engine mount is bad just by looking for signs.
One of the best ways that you can tell that you have a bad motor mount is if it is drooping to one side. An engine is meant to be level. If it is tipping in any one direction, that is a very strong indication that you have a bad motor mount.
As your engine moves around the engine bay, it can cause an exhaust leak. Exhaust leaks are pretty easy to distinguish. A pinging or knocking sound coming from the exhaust is typical. This happens because there’s not a lot of free play in the exhaust, so when it’s stressed, it’ll crack or blow a gasket.
There isn’t a lot of extra room in the modern engine compartment, which means that things can easily get cut or broken when they move. This is exactly what can happen to hoses and belts when a motor mount fails. A broken radiator hose can quickly cause a lot of damage if it runs your Altima out of coolant.
Related: Nissan Altima Bad Serpentine Belt
If you see their engine is damaged, and that there’s some corresponding damage on the frame, that is a telltale sign that you have a bad motor mount.
There are many reasons why your Nissan Altima could end up with a bad motor mount. Here are the most common ones:
One of the most common reasons that a motor mount will fail is when it gets damaged in an accident. Even if it’s a minor fender bender, that will often be enough to cause some serious damage to the mount. That’s why even if you are in an accident and it’s not that bad, it’s always a good idea to take it into an alignment shop. You should really take it to a mechanic and have them take a look and make sure there’s nothing else wrong.
If you put enough mileage on a vehicle everything will eventually break. The motor mounts are no exception to that. This is particularly true because most motor mounts have rubber bushings. They will dry and crack as they age even without mileage being put on the vehicle. Some motor mounts are liquid filled. This provides great vibration dampening, but when they go bad they do it in a hurry. You can usually tell when one has gone bad, because they will be leaking fluid onto the frame. It’ll look like your engine mounts have an oil leak.
If your car has recently been in an accident, the motor mounts may have been replaced. But, that doesn’t mean that they were replaced properly. That’s why it’s important to find a good shop whenever you have a major repair done.
There’s no perfect answer to this question. It’s going to depend a lot on how often you drive, whether or not the vehicle’s ever been in a collision, and what the motor mount is made out of. The best thing that you can do is have them looked at whenever you’re getting your vehicle serviced. Although, you should reasonably expect it to last for at least seven years.
Good luck finding out what’s going on with your Nissan Altima. Just remember while bad motor mounts are common, there can be other causes that would make your vehicle vibrate. It can be something as simple as a misfiring engine. Although, you should get some sort of trouble code if that were the case.
Your Nissan Altima’s braking system is the most important safety feature on the vehicle. If it does not work properly, it can put you in a situation where you can be injured or killed. There are quite a few different situations that can cause a caliper to stick.
One of the most common causes of sticking brakes is caliper bolts. These bolts have to hold the caliper in place, while at the same time allowing for some movement.
Brake caliper bolts are protected by a rubber boot. This rubber boot protects them from the elements and assures that they stay lubricated. Replacing these bolts is not very challenging.
There are notches in your Altima’s brake pads that let them slide back and forth from the rotor as the brakes are pressed. If something gets into these slides, the pads may not disengage from the rotor all the way.
This problem is often caused by bad shims or junk getting in the way. When this happens, the pads are almost certainly going to be worn incorrectly. As you replace the shims and clean everything up, go ahead and replace the pads too.
Your Altima’s disk brakes use pistons to push the brake pad into the rotor. These pistons have a rubber seal around them. This seal can go bad and the piston will start to lose its free movement. If this is the case, the caliper will almost always need to be replaced.
The brake hose that attaches to the Altima’s caliper will often cause the brakes to stick. They may appear to be fine on the outside, but can break apart and collect debris on the inside.
When this happens, it effectively traps pressure in the line. This keeps the brakes from releasing all of the way, and they stick as a result. Replacing the hose is easy. We recommend if you have to do one, you may as well do all of them. You’ll need to bleed the brakes afterwards.
If something has pushed a metal brake line into the chassis it can cause a crimp. Most of the time, this is done by someone with a floor jack really not paying attention to what they are doing. If this happens, you’ll need to replace the entire affected brake line.
Your Altima’s braking system is the most important part of the vehicle. If it is sticking, and you can’t easily figure out why, take it to a reputable shop. If there is anything that you would like to add, please leave a comment below. Good luck!
A sputtering engine can indicate a number of problems. If your Nissan Altima has a sputter, it is most likely going to be caused by bad fuel system, ignition system, MAF sensor, or bad catalytic converter.
Your Altima’s engine is a giant pump. It pulls in air (where it is measured by the mass airflow sensor). The air is then guided into the cylinder where fuel is added and compressed. Once compressed, the mixture it is ignited by the spark plugs. It is then expelled through the exhaust, where it is then scrubbed by the catalytic converter before being sent through the exhaust pipe.
Before diving into our list of the most common reasons that a Altima’s engine sputters, make sure to check for trouble codes if you have a check engine light on. This can radically reduce the time it takes you to diagnose the problem.
Any failure in the process listed above can lead to a sputtering engine. Here are the most likely causes of sputtering:
Your ignition system is more than just the spark plugs. It relies on data from the crank and cam sensors to time the spark properly. The coil or coil packs need to be strong. The spark plugs themselves can go bad over time. Although with a modern vehicle, it should be able to go near – 100,000 miles without the plugs showing much damage.
If you do have a problem with the ignition system, you’ll more than likely get a diagnostic trouble code that indicates that there is a problem with the ignition system, such as P0300 (Random Multiple Misfire) or P030X where X represents the exact cylinder that is misfiring.
If there is reason to believe that the ignition system has gone bad, take a look at the spark plugs first. They can tell you a lot about what is going on with the engine. Here’s a more in depth guide on bad spark plugs.
If the plugs look fine, check the spark plug wires (if so equipped), make sure that they look good (not dry rotted, not melted). An old trick that you can do to check them is to make sure that they are not bleeding spark. Wait until it is dark, turn off the headlights and check under the hood. If you see spark coming from the wires, replace them and hopefully that will solve the problem.
If the plug wires check out, you’ll need to test the coil packs themselves. You can do it with a voltmeter. Here’s a great video to help you with that.
The next item on the list would be the fuel system. The fuel system starts with the Altima’s fuel pump, which will be in the gas tank. It sends fuel through the fuel lines and filter to your its fuel injectors.
There needs to be enough fuel pressure for the fuel to properly atomize at the injectors. If there is not the engine will sputter like crazy, as it will be starved for fuel.
Most vehicles have a port to manually check the fuel pressure. That’s a great place to start. You’ll have to look up where it is for your particular model year and engine combo. But, they usually aren’t hard to access.
If the fuel pressure reading is below where it needs to be, checking and replacing the fuel filter would be the first thing to check. It’s easier to get to than the fuel pump. Otherwise, you’ll more than likely have to drop the tank and replace the fuel pump.
Before going through all of that though, make sure to inspect the fuel lines for any crimping or damage.
If the pressure looks good, you’ll need to determine if the injectors are clogged or leaking. Smell for gas right after running the engine. That’s a strong indication that a fuel injector is leaking. If it is leaking, consider it a fire hazard and don’t run the engine again until the injector has been replaced.
Further Reading:
Nissan Altima Fuel Filter Diagnosis
Nissan Altima Fuel Pump Diagnosis
A bad catalytic converter will cause your Altima’s engine to sputter. It scrubs the exhaust to remove pollutants. When a converter goes your vehicle is effectively choked. The two most obvious signs that one has gone bad will be engine sputtering and a rotten egg smell.
If the catalytic converter has gone bad, it will show itself the most when you need power. When the engine is idling, it may not sputter at all. As it revs up, more exhaust is created at one time. This leads to a back pressure increase, which chokes the engine from the exhaust side.
You’ll need to replace the catalytic converter if it is clogged. The most common OBD II codes associated with this code are P0420 or P0430.
Keep your nose open you should smell a bad smell coming from a bad catalytic converter.
The mass airflow, or MAF, sensor checks the air volume and temperature as it enters the engine. It’s one of the most important sensor that your Altima has. Just like the air filter that protects it, it can get dirty. When it gets dirty it can’t read the air entering the engine properly and your engine will sputter.
The mass airflow sensor is really easy to get to. It’ll be between the intake manifold and the air filter. If you do have to clean it, make sure that you are using mass airflow sensor cleaner, and nothing else. Otherwise you can damage it. Here’s a great video on how to properly clean a MAF sensor.
Further Reading:
Nissan Altima MAF Sensor Diagnosis
Engine sputtering is a tough problem to track down. The above list is not everything that can cause this problem, but it is a great start. If you find out what happened to cause your car to sputter, please come back and leave a comment. Good luck!
One of the more common issues that can occur is a vehicle that shakes when accelerating. If your Nissan Altima is shaking when accelerating, it’s something that should not be ignored. While the vibration can be annoying, it is often indicative of a serious problem.
Vehicle speed matters when you feel a vibration. Different problems are going to show themselves when driving at different speeds. If you’ve figured out that the problem is only happening when you are accelerating your Altima, that really helps narrow the problem down. The speed of the vehicle can help even more.
For instance, a vehicle that shakes when braking is going to have almost no overlapping causes with a vehicle that shakes when accelerating. For this reason, we’ve tried to include the most common speed associated with the different shaking causes listed directly below.
There are quite a few reasons that your Altima would shake when accelerating. Here are the most common ones. They are presented in a somewhat logical progression.
Vehicle Speed: A Misfire can be felt at any speed, but is most noticeable at low RPM.
A misfiring engine is one of the most common reasons your Altima will shake when accelerating. A vehicle’s ignition system consists of spark plugs, coil packs, and maybe plug wires. If it is an older model, it’ll have a distributor and coil instead of coil packs.
If any of these ignition components fail to deliver enough spark, your vehicle will experience a misfire. With a misfire, you will almost certainly get a check engine light. Check the codes. You’ll more than likely have P0300 (Random Misfire) or you’ll get P030X, where the misfiring cylinder number is represented by the X. For example, P0301 is a misfire in cylinder 1.
If you are going to diagnose a misfire from home, start with the spark plugs. Do they look like they are in good shape?
On the left here you can see a fouled spark plug. This particular plug was from a 5 year old Honda with 60,000 miles. Modern vehicles can and do foul plugs, particularly when cylinder deactivation technology is involved (as was the case in this example).
If you have a cylinder specific trouble code, there is an easy way to tell if it is the spark plug or coil pack. It’s called the swap test. Here’s how you do it:
Here’s a couple of good resources with more in depth info: Bad Spark Plug Diagnosis, Oil on Spark Plug Causes
Vehicle Speed: A bad motor mount is going to be felt when immediately accelerating. You should feel a vibration as you let off the gas, although it may not be as pronounced.
The motor mount is responsible for connecting the Nissan Altima’s motor to the chassis. It also needs to absorb a significant amount of vibration. There are a few different types of motor mounts, but the most common kind uses a rubber bushing to dampen the vibration.
If the motor mount goes out, the vehicle will shake quite a bit when you accelerate. It can still get worse though. A motor mount that has broken will allow the engine to roll around under the hood, and you’ll hear a clunking sound.
There’s more than one motor mount on a vehicle. If one of them goes bad, in addition to the extra vibration and shaking, it also creates extra stress for the other mounts. Here’s more on bad motor mount diagnosis.
Vehicle Speed: If you have a damaged CV joint, it’s most likely going to be noticed at all speeds. But, it could feel worse when turning, and when accelerating hard.
The CV joint is responsible for sending power to the front wheels of both front wheel and all/four wheel drive vehicles. The inner CV joint is most likely to be the part of the CV shaft that has gone bad.
More often than not, a bad CV joint is caused by a torn boot. The protective boot goes over the CV joint and keeps oil in and debris out. It is really easy to tell if the boot is bad. Just take a look. There will likely be grease all over the undercarriage around the boot. The boot shown above has a small tear.
Vehicle Speed: When a U-joint or driveshaft goes bad, there is usually a certain speed that the shaking is most pronounced at. If you keep accelerating, it’ll often “push through” and stop vibrating.
Rear wheel drive and all wheel drive vehicles use a driveshaft to transfer power from the engine to the rear wheels. The driveshaft is a simple tube that connects the transmission to the rear axle.
It is possible for the driveshaft itself to get bent. It is much more likely that a universal joint has gone bad. The universal joint has to change the direction in which something spins.
Look at the diagram below. As it wears out, there will be play between it and the driveshaft, which causes shaking when accelerating, and consistent shaking at certain speeds. Here’s a little more on the subject if you suspect this is what is going on with your vehicle.
Vehicle Speed: If you have a brake caliper, your Altima will shake more and more as you accelerate. You’ll also feel it in the steering wheel, and it’ll likely pull to the left or right depending on which side of it the caliper is sticking on.
A stuck brake caliper can happen to any vehicle. It can happen for a number of reasons, such as the piston in the caliper getting stuck, or a crimped brake line. More than likely, you’ll need to replace the caliper. Here’s more on how to tell if your Altima’s brakes are sticking.
It’s easy to tell if the caliper is bad.
Vehicle Speed: The shaking and vibration should be felt at any speed. It will feel worse at certain speeds and better at others. It depends on the vehicle, wheel in question, and how loose they are as to exactly what speed that would be.
Lug nuts can cause a vehicle to shake when accelerating. If there is any doubt in your mind as to whether or not they are all the way tight you need to get your Altima off the road as fast as safely possible and check.
Loose lug nuts usually show themselves after a tire change, rotation, or any other work that has been recently performed on the vehicle that would require the removal of a wheel. Get a torque wrench and torque all four to factory specs.
Vehicle Speed: You’re most likely to feel the vehicle shake as you gain speed. You shouldn’t notice much of anything under 30 miles per hour.
Tire balance can cause an automobile to shake when accelerating. Tires use wheel weights in order to achieve “balance”. This corrects any vibration that would otherwise occur. These weights can fall off over the life of the tire. When they do the tire will vibrate.
A poor wheel alignment can cause the tires to wear unevenly and the vehicle to shake. It is very likely that the vehicle is out of alignment if you’ve recently run up a curb, hit a large pothole, went over a speed bump too fast, etc.
Take a look at your wheels. If you see a spot where a wheel weight used to be, that’s a good indication that you found the problem. You’ll see the other wheel weights. The outline of a missing wheel weight is obvious and not something that you can easily miss.
A poor alignment will show itself in tires that are not worn correctly. If it is only recently that the vehicle has been knocked out of alignment, you won’t see any physical evidence by looking at the tires. Your mechanic of choice can check your alignment for you.
Vehicle Speed: Other engine issues can be felt at any speed, but is most noticeable at low RPM.
If your engine is running rough, you should check to see if the check engine light is on. There is a lot stored in the ECM that can tell you what is going on. Here are some of the problems that can cause a vehicle to shake when accelerating that can come from the engine:
Any of these issues can cause the engine to shake. While the list may look daunting, if there is not a trouble code related to the listed items stored in the computer, it’s unlikely that they are the problem.
Here’s more on a sputtering engine.
Clearly there are a number of issues that can cause your steering wheel to shake while accelerating. Hopefully this article helped you narrow them down. If you found out the cause of your Altima’s shaking issue, please leave a comment below. You may be able to help the next person who finds their way here. Good luck!
The main reasons for BATTERY/ALTERNATOR VISIT WORKSHOP:
1. Loose or bad battery terminal connection:
You can remove the terminal connections and clean them up just to be sure. Use some sand paper around the terminal post and at the cable end connection to make a clean up.
2. Main battery is near the end of its life:
If you have a voltmeter you can check the main battery before starting the car. It should have about 12.5 volts. If it is lower than 12, you need a new battery.Here is a simple test you can perform if you get Battery Defective message at start up. Let the car run for about 10-15 minutes. Then go turn off the car, make sure all the light are off and nothing is on for a 30 seconds or so. Then start your car back up again. Do you still get the Battery Defective message again? If you don’t than your main battery is not holding a charge properly especially if the car was sitting for a long time. You will be OK to drive the car, but replace the battery as soon as you can before it is not going to last very long.
3. Alternator problem:
More often than not, the real problem is the voltage regulator in the alternator. You can replace just the voltage regulator if you know that is the real problem. Otherwise you need to replace the whole alternator. Before you replace the alternator make sure that your battery is not the problem. One thing you can do to troubleshoot your car is to go to Advance Auto Parts or AutoZone and have them do a FREE alternator / battery check. This test may be able to point you in the right direction.
4. Secondary Battery / Auxiliary Battery:
Some Mercedes Benz models such as the E Class or the CLS Class have a secondary battery. This is a smaller 12 volt auxiliary battery that is used as back up. The system also checks the voltage of this battery and if it is lower than 12.6 volts you will get the error on your dashboard. So if you replaced the main battery and were wondering why you are getting the Battery/Alternator Visit Workshop message then check this battery as well. Before you start the car after it was sitting for a few hours or overnight, grab a multimeter and check the voltage at the secondary and the main battery. If you have less than 12.5 volts at either one, you know your problem.
This could be a case of an air leak in the suspension system which is causing the car to rise but is taking too long to reach normal driving level. Here the shock absorbers should be examined and listened to for air leaks. The air-hose connected above each shock should be checked as well. It is preferable to have this checked by a mechanic since they will be able to differentiate and diagnose.
There could be two possibilities in this case. First the Mercedes air suspension can drop when the car is parked for a few days because the air in the bags tends to seep out. However it levels once the pressure in the pump normalizes. On the other hand, there may be cases of updated pumps which do not provide sufficient pressure, preventing the system from rising completely. There are a few recalls of these and the local dealer would be able to provide more information whether the faulty component is present on this Mercedes car. The other possibility could be leaking rear shocks which can cause noises from the rear and make the car shake as well.
This is a fairly common problem with the airmatic suspension on the Mercedes E class especially once it completes 75,000 miles and is prone to face more problems as it ages. In this case the front suspension strut is leaking. Struts are more expensive to replace and cost approximately $1,000 each, however if you opt for aftermarket remanufactured units, it may be more economical. Strut replacement usually requires two hours of labor. Another possibility could be leakage from an air-line which is a cheaper repair. Since most Mercedes air suspension models are prone to leakage, it would be a good idea to begin by inspecting the Mercedes air suspension for leaks. Since the car appears to be more affected at the driver’s side, the driver’s side suspension strut could have failed.