11 Causes of Car Losing Power When Accelerating (Gas & Diesel Engines)

Last Updated on May 13, 2020

If you are driving your car and notice that you are losing power as you accelerate, there can only be one of two reasons for this. Either you do not have enough fuel in your vehicle or you do not have enough power.

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There are many reasons why your vehicle may be losing power, especially when accelerating. Some of these common causes are:

  • Mechanical problems such as: Low compression, clogged fuel filter, dirty air filter, clogged Exhaust Manifold
  • Malfunction of sensors such as: Camshaft position sensor, MAF sensor, oxygen sensor, crankshaft sensor and all sensors relative to the EFI system.
  • Malfunction of actuators such as: Bad injectors, bad fuel pump, bad spark plugs

11 Causes of a Vehicle Losing Power when Accelerating

There are a few different causes between gas and diesel engines. Below are the 11 most common reasons for a car or truck losing power when trying to accelerate:

#1 – Low Compression (Gas & Diesel Engine)

low compression

In order for a car’s engine to function properly and provide adequate power to the vehicle, there must be good cylinder compression throughout the combustion process. If the compression is low, then the power of the engine will be low. The result will be an engine that simply doesn’t function properly. Diagnosing low cylinder compression is the next step toward a solution.

#2 – Clogged Fuel Filter (Gas & Diesel Engine)

fuel filter

The fuel filter is located in between the fuel injectors and fuel pump of your vehicle. The job of the fuel filter is to screen the gasoline for any impurities which may exist in it. That way, when the fuel pump sends the gasoline into the engine, those impurities won’t be there.

The fuel filter is literally a barrier between the contaminants in the gasoline and the engine of your vehicle. If you were to have a dirty fuel filter or one that couldn’t perform its job properly because it’s damaged or clogged, then those contaminants would find their way into the engine and at some point, cause expensive damage.

Once that happens, the engine will eventually lose its power and the overall functionality of the vehicle will be impaired. Replacing your fuel filter is the most straightforward fix.

#3 – Bad Air Filter (Gas & Diesel Engine)

dirty air filter

The internal combustion chamber of an engine is responsible for mixing gasoline and air together in order to generate the power that is needed to run your vehicle. Before the air can enter the chamber, it must pass through an air filter that screens out bugs, debris, and other kinds of impurities that may exist in it.

If these impurities were to get into the engine, they could cause severe damage. However, air filters tend to get clogged after they’ve been used for a while.

Once an air filter gets clogged, it will limit the amount of air that can get into the internal combustion chamber. This will negatively impact the functionality of the vehicle because the engine won’t be able to generate a sufficient amount of power to run the car. Replace your air filter and you should be good as new. If you have a reusable air filter such as a K&N, simply clean it according to the manufacturer’s directions.

#4 – Clogged Exhaust Pipe (Gas & Diesel Engine)

clogged exhaust

There are two filters in an exhaust system; the muffler and the catalytic converter. The job of the catalyst converter is to cut down the amount of pollution generated from the exhaust gasses.

As for the muffler, its job is simply to decrease the amount of noise that is made. If the exhaust pipe or any of its filters were to get clogged, it would weaken the functionality of the engine by reducing its power and making the vehicle drive slow when trying to accelerate.

A clogged exhaust system is bad on any vehicle but it’s even worse on a turbocharged vehicle.

#5 – Camshaft Position Sensor Malfunction (Gas & Diesel Engine)

bad camshaft position sensor

The vehicle’s camshaft position sensor is responsible for gathering information about the camshaft speed of the vehicle and then sending it to the electronic control module (ECM).

This module is a computer which exists inside most cars on the road today. Once information about the camshaft speed is sent to the ECM, the computer will then manage the timing of both the fuel injection and ignition based on this information.

However, if there is a malfunction with the camshaft position sensor and it’s not able to send this information to the ECM, then the performance of the engine will be greatly impacted and likely won’t be able to function properly.

#6 – MAF Sensor Malfunction (Gas Engine)

MAF sensor

The main responsibility of a Mass Airflow Sensor is to measure the amount of air that flows into the engine and then report this amount to the Powertrain Control Module. From there, the module will use this information to calculate the load that is being placed on the engine.

If there were to be some sort of malfunction with the sensors, then the engine’s performance would be diminished.

#7 – Oxygen Sensor Malfunction (Gas & Diesel Engine)

bad O2 sensor symptoms

When exhaust gasses leave your vehicle’s engine, the amount of gasses which leave is measured by the oxygen sensor. The electronic control module then uses this information to figure out the real-time air-to-fuel ratio that exists in the vehicle’s engine.

The oxygen sensor is positioned inside of the exhaust stream. It enables the engine timing and fuel injection system to do their jobs efficiently. The oxygen sensor even provides support with emission control as well.

But if a malfunction were to take place with the oxygen sensor, then it wouldn’t be able to accurately send information about the air-to-fuel ratio to the electronic control module. This would cause the engine to start performing poorly and it would ultimately have a negative impact on the environment.

#8 – Bad Fuel Injectors (Gas and Diesel Common Rail Engine)

fuel injectors

Fuel injectors are an important management component of a vehicle’s engine. They are located within the fuel system of a vehicle and their main job is to spray fuel inside of the engine.

The computer of the engine is what controls the fuel injector and the specific time intervals and patterns in which the injector sprays fuel into the engine. That way, the engine can perform the best that it can under different driving conditions.

You will find that most vehicles on the road these days have fuel injectors in them. If a fuel injector were to become damaged or malfunction in some way, then the engine would not be able to generate a sufficient amount of power to run the vehicle. You can expect all kinds of engine performance problems to take place since the fuel injector is a crucial part of the fuel system.

#9 – Bad or Weak Fuel Pump (Gas Engine)

bad fuel pump

The responsibility of the fuel pump is to take fuel from the gas tank and transfer it into the engine of the vehicle. Not only that, the fuel pump ensure that the fuel is delivered at the right pressure so that it can meet the demands of the engine for maximum performance.

If something were to malfunction or go wrong with the fuel pump, there would be acceleration problems with the vehicle and the performance of the engine would ultimately be jeopardized.

Read also: Symptoms of a bad throttle position sensor

#10 – Bad Spark Plugs (Gas Engine)

bad spark plugs

Spark plugs are an important component of a vehicle’s internal combustion motor. After the ignition coil sends an electrical signal to the spark plugs, they transmit that signal to the combustion chamber so that its air & fuel mixture can be ignited by an electric spark.

If the spark plugs were to ever fail, then the engine’s performance would diminish and eventually fail altogether.

Read also: Causes of Car High Fuel Consumption in Diesel and Petrol Engines

#11 – Bad Ignition Coil (Gas Engine)

bad ignition coil symptoms

The ignition coils of the ignition system serve as an electronic engine management element which is responsible for converting the 12 volts of power generated by the vehicle into 20,000 volts. This amount of voltage is needed in order to generate the electrical spark which can ignite the air & fuel mixture of the engine.

If the ignition coil were to fail, then the vehicle would be unable to accelerate and its power would be lost.

Other Causes of No Power When Accelerating

  • Bad Turbo charger
  • Bad EGR valve
  • Bad Injection pump delivery valve ( Conventional Diesel Engine)

166 thoughts on “11 Causes of Car Losing Power When Accelerating (Gas & Diesel Engines)”

  1. My new 2020 RAV4 Hybrid XLE has lost power twice now in the 8 weeks that I’ve owner it.

    I want to ask if this can be in any way related to the hybrid mechanism. I reported this to toyota, and while they are recalling 5.8 millions cars due to faulty fuel pumps that cause their cars to stall, they have told me that it couldn’t be that with my RAV4 because it only happens at high speeds (without disclosing to me what constituties high. My problems were experienced first awhile pulling out of a driveway and then driving along a road at approxmately 35 mph.

    I am ready to send this car to the junk yard (because Toyota does not want to either replace the fuel pump or take the car back) and I consider it UNSAFE AT ANY SPEED, and they’re remedy is to simply call them if it happens again. HOW MAQNY TIMES DOES IT HAVE TO HAPPEN? Does it have to stop when it leads to an accident?

    It is a nice car. Just prone to stalling. Well actually it has three other issues, but I won’t go into that here.

    • When you say “lost power”, do you mean the vehicle feels sluggish or has stalled altogether?

      To check if your vehicle is affected by a recall, you can enter your VIN on this website: https://www.nhtsa.gov/recalls

      If you don’t see a recall listed for your vehicle, it’s probably an unrelated issue. However it may still be covered under warranty, so check with your local dealership on that.

  2. I have chevy camaro z28 when I accelerate to 50 it start losing power….. It won’t go past 50 or the 2 on rpm……. What is the problem

  3. I got a fiat palio 1.2, it loses power while am driving, I did check petrol pump , it’s working properly, new spark plugs, now I dnt know what else to check

    • Can you describe “loses power” in a bit more detail? Is the car hesitating, stumbling, or does it just feel down on power?

      Does the power ever go back to normal? If so, when?

  4. I have 1989 Dodge Ram50 2.6 New long block after market Weber carb new fuel pump new new fuel filter distributor no cat or computer any more have a after market header pretty much everything is new . When I’m driving under load in 4th or 5th gear half throttle the engine looses power but if I let off or go past the half way spot it picks up power . Just had the carb rebuilt and it didn’t help the problem timing is right on also
    Please help thanks

  5. I have a 1.4 v reg ford fiesta,it goes very slow and I have to give it 5000 revs in first gear to get going at all really.Oil was low topped it up but the car is still the same.

    • Check to make sure there aren’t any stored codes. If you don’t find any, pull the spark plugs to see if they look black (rich) or burnt (lean). You might want to do a smoke test to check for vacuum leaks, and a fuel pressure test to make sure you’re getting enough fuel to the intake manifold.

  6. my L300 loses power when accelerating but after some minutes when you start the car it responds , i have changed fuel pump three times and fuel filter once but it persisted

    • Are there any stored codes? You may want to do a smoke test to check for vacuum leaks, and a fuel pressure test to make sure you’re getting enough fuel to the fuel rail.

    • I am having the same issue. I have changed fuel pumps 5 different times, changed fuel filters twice. The air filter was checked and certified ok. The mass airflow sensor checked n OK, oxygen sensor OK, fuel injectors OK, changed spark plugs. Finally, it was discovered that I have clogged exhaust. When the exhaust was brought down, I was in shock. Its a marvel that the car was able to move at all. Here is my advise, run an OBD diagnosis, it will identify the issue l easily and you won’t have to spend money buying parts you never needed. PS, I’m in the same country as u

  7. my citroen xsara picassa is losing power as I change gears. It is a momentary thing and she drives correctly afterward. Once into 4th gear, she drives fine. I’ve changed the fuel filter and the air filter. What to do now? I can’t afford to go to a garage.
    Is she still safe to drive?

    • It could be, but there are a lot of components that can cause you to lose power while accelerating. Are there any check engine lights that could help you narrow down the problem?

      • I also have a 2015 Jeep Grand Cherokee that does this. It hits around 60 and loses power till back around 40. The traction light comes on.

        • My advice to you guys would be to search the Jeep Cherokee forums to see if this is a common issue with a known solution.

  8. I have a 2005 Buick RNDV CXCLU that usually drives smoothly; however, some obstacle is causing the vehicle to slow down from regularly functioning to an immediate snail’s pace.
    Two times mainly. One time is when I travelled from the city limits going approximately within 35 miles around a bend slightly uphill onto a main highway to 55 miles per hour. However, the car almost came to a standstill going up the bend. It would not accelerate, decreased in speed, and made like a loud hornet-like buzzing noise. I am assuming the sound came from the engine. I have made sure to avoid traffic and not pull out unless the road is completely clear. I no longer drive it.
    The other time is when I pulled out from the driveway; however, the car continued to stall a similar way. The vehicle does not sputter, but instead, makes a zooming-like sound standing still. I have had to park the car completely. It needs to be repaired as soon as possible. I would most appreciate any suggestions you may have and thank you for your expertise.

    • See if there are any codes stored from a current or previous check engine light. That may be able to point you in the right direction.

      It sounds like you might have a transmission issue, but it’s a bit hard to say. You will probably have to have the vehicle towed to a mechanic unless you have a friend who is savvy with cars that can help with the initial diagnostic work.

  9. I have a 2009 Toyota Camry it has never have me problems before but today I was on the freeway and it started shaking and losing power then the check engine light began to flash and I pulled over after sitting there for about 15 min I started it again and made it home with no problem it did fine whatcaused it to shake lose power and check engine light

  10. My Toyota Corolla S 2007 model have this error code P0016. The engine sounds okay but it is sluggish when going up a hill or overtaking. Can Crankshaft sensor, Camshaft sensor or VVT has correlation with loss of power and the error code? One mechanic told me is a timing chain issue but I’m sceptical about it as the engine sounds good. I don’t want to be at the mercy of any mechanic, I want to know cause before handing it over to mechanic.

    • My guess is that VVT is disabled while this code is thrown, putting the cams in a more conservative setting and giving you less power. You probably wouldn’t notice a difference in engine sound if VVT is disabled.

      You can try getting a second opinion from another mechanic, but any ideas you get will be a guess without further diagnostic work. Also if you google this error code and search Corolla forums, you may very likely find a common cause.

  11. Hi, I’m driving a polo classic 2003 model 1.4 16Valve and it stalls while I’m driving. I’ve used a carburetor cleaner to spray an EGR Valve and I managed to drive for about two weeks without problems. Then it started again. What could be the problem

  12. i have RAV 1998, i has power loss even after replacing spark plug, fuel filter, removing clods in the exhuasion pipe. what can i do to solve power loss

  13. My car is a 2012 Nissan Rogue. My went from slowing down to not moving. I changed the catalytic converter and the throttle body and it still has a problem.

  14. Hello Fellow Mechanics! I have a Mazda MPV 2003 van and I have a drastic loss of power! when i press the pedal it has no power at all! no power that i could not even get up onto a trailer to haul it. It idles fine but the second i add power it just go “I know i cant, I know i cant, I know i cant” so today i removed the exhaust manifold and replaced the spark plugs with NKG spark plugs and new manifold gaskets. I also made sure on all the clips that no corrosion is on the electric connections. I do have a hole in my exhaust and i believe it could be the exhaust sensor but beyond that i have no idea what is going on? can i possibly have some tips for were to start to look?

    • Were there any check engine light codes? You could do a fuel pressure test to make sure you have enough fuel. Put a screwdriver on the back of each injector with the handle up to your ear to make sure you can hear each injector firing.

      There are lots of tests you can do that will at least help you narrow it down. If you can figure out if the problem is insufficient air, fuel, spark, or timing that will help you a lot. Good luck on your search.

  15. My 66 Mustang suddenly cut out at 50 mph. I coasted to a stop and was able to restart after a minute. It continued for the rest of the short trip; run, stall and restart after a minute, wouldn’t start right away but would after a minute. Engine doesn’t seem to be mis-firing or low on power, at least until it loses all power that is.

  16. I have a BMW 325i 2007 and the EML light has come on and loss of power even when i put my foot down on the accelerator it just sounds and feels limp. drove home on low speed which was fine. i understand their could be many causes but just curious if its a serious issue?

    • Sounds like your vehicle may be in limp mode. I don’t know if it’s a serious issue, you’ll have to get the code scanned and maybe do a bit of diagnostic work to pin down the problem.

  17. I have a 2012 buick verono that loses power and stalls. It doesn’t give off an accurate code & the check engine light is not on. It’s been to 2 mechanics and still no resolution. They’ve changed sensors, canister, air flow mass, Cadillac converter and still no resolution. Any tips????

    • I think you’ll have to do some more testing. Look for symptoms to help you narrow down the problem. Any smoke out of the exhaust? Does it idle rough? Any strange noises? Where are the noises coming from?

      A few tests to consider are a smoke test (tests for vacuum leaks), a fuel pressure test, a compression test (checks overall engine health), and a leak down test (after a bad compression test, this will tell you where combustion gases are going).

  18. My car is a Chrysler 200 2012 and my car stopped running while driving on the highway. It was driving fine and suddenly it slowly came to a complete stop. The car was still on but the gas wouldn’t accelerate while attempting to press the gas pedal. I turned it back on after having it off for 5 mins to get somewhere safe but it only drove half a mile before slowly coming to a complete stop again.

  19. I have a Kia Rio 2012, when I accelerate it would sometimes lose power for a moment, no power at all. I would pump the gas pedal 2 or 3 times and it would be back to normal. The check engine light doesn’t switch on. What could be the reason for this?

    • I am not sure. Does it seem like the car hesitates or stumbles, or does the throttle stop working entirely?

      Could be a problem with the throttle pedal assembly, could be a mechanical problem with the engine. You’ll have to get the issue diagnosed by a technician before you can really know for sure.

  20. my car is losing power especially when you climbe step hill or when i stop on a stop sign to want to move forward …is kia rio 2016 hatchback

  21. I have a 06 Kia optima and I’ve changed the map sensor changed the plugs and check my catalytic inverrter but my car has no power when accelerating but starts up and idles fine what could be the problem

  22. I have an 04 grand am. I’ve replaced both 02 seconds and cut off the catalytic convertor.I still lose power between 3500 and 4000 rpms. Only code is for 02 sensor. Any ideas?

    • I don’t know, it could be a number of things. Hook up a scan tool and check your fuel trims. How does the air fuel ratio look? Is it running rich or lean?

      Have you tested for vacuum leaks?

  23. Hi, i have a polo citi vivo 2017. It lost power when accerlarating then i changed the plugs. Im not sure if i bought the right plugs or wat.

    • If you bought the plugs from a local parts store they should be able to help you confirm. If not, there are a couple things you can check.

      Check the length of the spark plug and the number of electrodes, they should be the same on your old and new spark plugs (assuming the original plugs were correct). Next, look up the plug gap for your vehicle and check this with a plug gap tool. Finally, check the heat range on the plugs to make sure they match the original plugs. Different manufacturers have different ways of indicating the plugs’ heat range, so you’ll have to look up this information for both the original plugs and the ones you bought.

  24. Good evening
    My car is a 2013 Ford Focus 1.6. The head gusket had to be flushed.
    Now it doesn’t have power for steep hill climbing.It makes a lot of noise as if its a diesel car.

    • Search Google for some local mechanics near you. For pricing, call a few of the shops and ask what they charge for the work you want to have done. Next, ask around your community and see how people feel about the different shops. Good luck on your search.


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