5 Common Causes of an Engine Misfire (and What It Feels Like)

(Updated on April 19, 2021)

When a car has a misfire, it means that internal combustion in the cylinder did not finish completely. The car will still be able to run and you’ll be able to drive it, but you’ll start to notice the engine jerking a lot.

This could be followed by exhaust smoke coming out of the tailpipe, the smell of gas, and loud popping sounds. When you experience these symptoms, you likely have an engine misfire (aka cylinder misfire).

You’ll want to get your vehicle examined by a mechanic right away if your home mechanic skills aren’t up to par yet. If you let the symptoms above go for too long, it could end up damaging your engine.

What Does an Engine Misfire Feel Like?

driving with engine problem

An engine misfire will be recognizable to the driver because their engine will feel like its stumbling for a few seconds and then regain its pace again. The number of times this happens will depend on the seriousness of the misfire.

If at least one spark plug is not firing correctly then it will cause the engine to malfunction and run terribly. The car may still move, but you will notice an increase in your vehicle’s exhaust emissions, a lack of acceleration and a reduction in the engine’s power.

If you step on the gas pedal and it takes awhile for your car to go faster while leaving behind a cloud of smoke behind you, this probably means you have a misfire.

At this point, your engine will require more fuel than necessary just to operate at its normal level. This will result in you having to spend more money on gas.

What Does an Engine Misfire Sound Like?

The best way to describe the noise a cylinder misfire makes is to think of popcorn kernels randomly popping. In some vehicles it can also sound like a “chug” or sneeze. While a backfire is technically different than a misfire, a loud “bang” or “poot” can be heard from both.

Top 5 Reasons Your Car Misfires

There are lots of reasons as to why a car would misfire in the first place. To help you understand what might have been the cause of your car misfire, below are five of the most common causes that someone could experience in this situation.

1) Air to Fuel Ratio Imbalance

One of the main reasons for an engine misfire can be attributed to an imbalance in the air to fuel ratio within the internal combustion chamber. This usually means there is not enough fuel and too much air being mixed together.

For the combustion to be successful, the mixture needs a specific proportion of fuel for the amount of air entering the engine. Otherwise, you will notice the cylinder misfire while your engine is idling. But when you’re driving at faster speeds, the symptoms of the misfire will go away.

The reason there may be an imbalance could be due to a bad fuel pump, clogged fuel filter, or a bad air flow sensor.

2) Ignition System Issues

dirty spark plug

There could be a problem coming from any one of the components in the ignition system. Perhaps the spark plugs aren’t creating an adequate spark for the internal combustion chamber.

You could also have a worn-out ignition coil, ignition cables, rotor, or distributor cap. If any of these problems exist, the internal combustion chamber’s air and fuel mixture won’t be able to ignite properly.

The weak spark will cause an engine misfire, but you might not notice right away. But as you operate the vehicle, you’ll feel its jerkiness very well.

3) Transmission Issues

bad torque converter symptoms

There are times when the misfire might not even come from your engine. It could come from the transmission instead. If your car starts to jerk around like an engine misfire had occurred, your transmission may not be able to adequately shift up or down.

You will notice this more when you’re driving at faster speeds. This is a bad situation like any other misfire and you need to have it repaired right away.

4) Mechanical Problems

how an engine works

Your vehicle is made up of many mechanical parts which contribute to the functionality of the engine. There are piston rings, camshaft lobes, valves, and cylinder walls.

If any of these parts were to get worn out, it could cause an engine misfire. The same goes for when there’s an intake manifold gasket leak or a head gasket leak.

Other possible mechanical issues may include a bad fuel injector or damaged rocker arms. Check the timing belt to see if that’s installed correctly too because it may have slipped.

You will know when there’s a misfire caused by mechanical issues because there will be a thumping feeling from the vehicle that will never go away, regardless of your speed.

5) ECM Problems

bad ecu

Sometimes there may be a glitch in the engine control module or the central computer of the vehicle which manages the engine. Any minor glitch there could throw off the combustion process and cause a misfire.

Fortunately, there is an easy remedy to this type of problem that works most of the time. If you simply disconnect your battery for a few minutes and then reconnect it. It’s similar to rebooting a computer at home and this should solve any minor glitch or bug in the computer system.

If the bug still exists after that, then you need to have the central computer examined at the dealership where you got the car.

29 thoughts on “5 Common Causes of an Engine Misfire (and What It Feels Like)”

  1. good information i think my have got a problem on fuel filter because the engine misfire occur when i start a engine but for a short time disappear.

    Reply
  2. I have replaced the spark plugs, weird and ignition coil pack. All new. Did a combustion test, that’s good. Injectors are good, fuel system is fine as well. Car still misfires.

    Reply
    • I had new spark plugs and coils, and got a misfired on the road. Changed the spark plug and still misfired, it was a defective coil pack. Fortunately I had and extra one and replaced it. Problem fixed.

      Reply
  3. my car ignites well,but when i start accerelating to move on,engine kind of gets choked and the pulling is lowered.when i enter rough road with corrogation,the car tends to gain and lose power simultaneously as if something is blocking engine and releasing it.i have replaced valves,rings,oil,filter,plug.what i dont know is whether there might problem with shooting coil.advice!

    Reply
  4. Question…

    Bought my son a 2008 Milan 4cyl. It’s miss fires only when the engine is cool. After about a half mile it stops. What could that be?

    Reply
    • I’m not sure. Unfortunately it could be a lot of things.

      When was the last time the spark plugs were replaced? It may have weak ignition, which would mean new plugs or ignition coils. Perhaps an injector is leaking or some other related fueling issue. If it’s throwing a check engine light, that would be a good place to start.

      Reply
  5. I have a 2008 dodge ram 1500 6 cyl my truck has been misfiring and the right side cylinders are running rich but not sure if it would be the o2 sensor the back fire sounds like a machine gun very rapid popping

    Reply
    • Figure out which parts are duplicated across banks, then start testing and troubleshooting the duplicate parts on the bank with the misfire. For instance some vehicles have one catalytic converter per bank of cylinders.

      Reply
  6. Well, I have a 2007 Honda Pilot. I have replaced all ignition coils, spark plugs, VTEC solenoid. All plugs are still misfiring. What does this sound like?

    Reply
      • My 406 jumped timing & valve head cut off. After fixing it back spark plug number 4 is not firing at all &
        plenty smoke comes out of the tailpipe & around the engine.

  7. i have a 2005 Pajero (3.5) and it has a misfiring problem which is erratic (sometimes is there sometimes not). sometimes it fails to start and i need to prime it for it to start and idle

    Reply
  8. I have an 04 f150 the truck misfires going up steep hills or on highway when my soeed is leveling out. And just recently will die at a stoplight or when at idle. Ive replaced the plugs, got new fuel injectors. Help please

    Reply
    • It’ll be hard to say what the problem is without a bit more testing. A smoke test will check for vacuum leaks. Replace the fuel filter if it’s been a while, maybe perform a fuel pressure test.

      Reply
  9. I have a 1985 coroll carburated that starts well in cold.after driving upand down a steep hill, she started to loose power and was choking and loosing pwer when giving fuel. its a carb. carb got tuned a minths ago and ran nice, timing, oil change and crankshat seal got done 2 weeks ago and ran nice for a few days. Parked it for 2 week but then started burping after 30 min use. changed the plugs, air filter and nothing going better beside start

    Reply
  10. I have an 03 jeep gran Cherokee with an 4.0 motor that MI’s fires on occasion mostly at higher ongoing speeds, when it happens I pull over, plug in the diagnostic tool, delete the multiple misfire codes and be on my way .runs good again till the next time. What’s the possible issue sound familiar to any one?

    Reply
    • Deleting the codes won’t solve the problem. The issue could be caused by bad spark plugs, ignition coils, carbon build up, clogged or leaking injectors, water in the combustion chamber, and any number of other things. You’ll have to do a bit more diagnostic work to know for sure.

      Reply
    • Most vehicle cut fuel when coasting (and the throttle is closed), so what you describe as a miss may be caused by something other than a misfire.

      For instance, if one cylinder has low compression, that cylinder will not have as stong of vacuum while coasting, which could theoretically make the car feel like it’s moving forward in a way that is less than smooth. You could try doing a compression test to narrow that down, and a leak down test if your compression test comes back with disappointing results.

      There could also be some imbalance in the engine’s rotating assembly causing excessive vibration.

      Reply
  11. my car nissan sunny 2005 ignites well,but when i start accelerating to move on,engine kind of gets choked and the pulling is lowered.when i enter rough road with corrogation,the car tends to gain and lose power simultaneously as if something is blocking engine and releasing it.i have replaced valves,rings,oil,filter,plug.what i dont know is whether there might problem with shooting coil.advice!

    Reply
  12. I have 2016 Toyota corolla, when my car is moving on a normal speed there is no problem but when l start to over speed , then there is hot in the speed and the car start jerking and when you step on the accelerator pad it does not move as you except.l have change control board, plugs, coil , injectors but still the problem persist.

    Reply

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