5 Common Causes of Engine Misfires (And What They Feel Like)
You’re on your way to work or running errands when suddenly your car starts shaking or making noises. As the dreaded “check engine” light rears its ugly head, you can’t help but worry about what’s going on under the hood of your car.
You’re probably suffering from an engine misfire, a common problem that affects many cars on the road today. But what exactly is a misfire? What does she feel and sound like? And most importantly, what causes a misfire in the first place?
What is a misfire? A misfire occurs when one or more engine cylinders fail to burn the mixture properly, causing a loss of power and a jerky engine. Your car will still run and you can drive it, but you’ll notice the engine is jerky.
You’ll then experience exhaust smoke from the tailpipe, a gasoline smell, and a loud banging noise. If you notice these symptoms, you probably have an engine misfire (also called a cylinder misfire).
Misfires reduce engine performance and efficiency, and can cause damage to the engine and catalytic converter if the misfire continues for an extended period of time.
What does an engine misfire feel like? Driving with engine trouble
Engine misfires are noticeable to the driver because the engine feels like it’s sputtering for a few seconds and then returns to its normal rhythm. How often this happens depends on the severity of the misfire. If at least one spark plug doesn’t fire properly, you’ll experience malfunctions and problems with your engine running. Your car will still run, but you’ll notice increased exhaust fumes, slower acceleration, and reduced engine power.
If your car takes a long time to pick up speed when you step on the accelerator and you see a plume of smoke behind you, you may have a misfire.
At this point, your engine will need more fuel than it needs to operate normally, which will result in you spending more money on gas. What does a misfire sound like?
A misfiring cylinder is best described as the sound of random popcorn popping. In some vehicles, it may also sound like a “gurgling” or sneezing sound. Although misfiring and misfiring are technically different, in both cases you will hear a loud “pop” or “pop” sound.
The 5 Most Common Reasons Why Cars Misfire
There are many reasons why a car may misfire in the first place. To better understand what causes your car to misfire, here are five of the most common reasons this situation can occur:
1) Air-fuel imbalance
One of the main causes of engine misfires can be attributed to an imbalance in the air-fuel ratio in the combustion chamber. This usually means not enough fuel and too much air.
For combustion to be successful, the mixture must have a certain ratio of fuel to the amount of air entering the engine. Otherwise, you will notice a cylinder misfire while the engine is idling. However, the misfire symptoms disappear when driving at high speeds.
The cause of the imbalance could be a defective fuel pump, clogged fuel filter, defective airflow sensor, bad/old gasoline, etc.
2) Ignition System Problems
The problem could be due to any of the components in the ignition system. Perhaps the spark plugs are not producing enough spark into the combustion chamber.
It could also be that the ignition coils, spark plug wires, rotor, or distributor cap are worn out. When any of these issues are present, the mixture in the combustion chamber will not be able to ignite properly. A weak spark will cause your engine to misfire, which you may not notice right away. However, when you drive the car, you will notice a noticeable jerky feeling.
3) Transmission Issues
In some cases, the misfire may not even be coming from the engine. It may come from the gearbox instead. If your car starts to shake as if it is misfiring, your transmission may not be able to upshift or downshift properly.
This will be more noticeable when driving at high speeds. This is as disastrous as any misfire and should be repaired immediately.
4) Mechanical Issues
Your vehicle is made up of many mechanical parts that contribute to the functioning of the engine. There are piston rings, camshaft cams, valves, and cylinder walls. If any of these parts wear out, a misfire can occur. The same can be true if the intake manifold gasket or cylinder head gasket is leaking.
Other possible mechanical issues include a faulty fuel injector or damaged rocker arms. The timing belt may also be slipping, so make sure it’s installed correctly.
If your vehicle has a sluggish feeling that doesn’t go away regardless of speed, you’ll know the misfire is due to a mechanical issue.
5) ECM Issues
Sometimes, the Engine Control Unit, or the vehicle’s central computer that controls the engine, can fail. Even a small mistake can disrupt the combustion process and cause a misfire.
Luckily, there is a simple solution to this type of problem that works in most cases. All you need to do is disconnect the battery for a few minutes and then reconnect it. This is similar to rebooting your computer at home and will fix any small errors or bugs in your computer system. If the error still persists, you should have the central computer inspected by the dealer where you purchased your car.
Misfire Symptoms
When your engine misfires, you will notice a few key symptoms. It is important to pay attention and not ignore them, as small issues can turn into costly repairs if left unattended.
Shaking – One of the first things you will notice is a shaking sensation throughout the vehicle. This can be caused by uneven firing of the cylinders in the engine.
Rough Idling – If your car is idling rough, you may notice more vibration than normal. This can be a telltale sign of an engine misfire.
Flashing Check Engine Light – A flashing (but not lit) check engine light could indicate that your engine is misfiring. This could be a red flag, especially if combined with other symptoms.
Rough Acceleration – Another sign of an engine misfire is rough acceleration. If you feel your car shaking, it could be a sign of an issue with your engine.
Loss of power – When your engine misfires, it struggles to maintain proper combustion and your vehicle may lose power.
Popping noises – Popping or misfire noises from the engine could be a symptom of a misfire. This is caused by uneven burning of fuel in the engine.
Fuel smell – While not a direct symptom, a strong smell of gasoline is an indication of an underlying issue with fuel burning improperly, causing a misfire.
Exhaust Smoke – If you notice excessive exhaust smoke, it could be a sign that your engine is misfiring and letting unburned fuel into your exhaust system.
However, it is not the best idea to rely on a misfire going away on its own. In most cases, it is better to address the underlying cause rather than waiting for it to go away.
What does it mean when a misfire disappears when accelerating?
If a misfire disappears during acceleration, it usually indicates that the underlying cause is a fuel delivery problem, not an ignition problem. This could mean that there is a problem with the injectors, fuel pump, or fuel pressure regulator, which are responsible for delivering the right amount of fuel to the engine.
When the engine is idling or running at low speeds, not enough fuel can get into the cylinders, causing a misfire.
