Car Engine Misfiring: Causes and Fixes

car engine misfire

A car engine is a combination of different components. For an engine to run smoothly, every component and proper air-fuel ratio all come into play. A problem, damage or any issue within the components or in case of a disrupted air-fuel ratio, an engine fails to run properly. This can lead to problems like a car engine misfire. Driving with an engine misfiring issue can cause further damage to the engine and drivers may end up bearing a bigger expense.

Fortunately, if you know the causes, this problem can be avoided beforehand. We will go through some common causes and symptoms of car engine misfire along with some effective ways to overcome the issue.

Causes of a Car Engine Misfire

bad spark plugs can cause car engine misfire
There can be several cause of a car engine misfiring such as bad spark plugs or ignition coils

An engine misfire is among the most common car issues drivers face in their vehicles. Although you may still be able to drive a car with an engine misfiring problem, it is advised not to do so. This bad driving practice may lead to premature wear of components and in some cases cause an engine failure.

If you know about the causes of this problem, it becomes relatively easy to overcome the issue. That said, let’s go through some common engine misfire causes.


One common cause of a misfiring engine is damaged or failing spark plugs. In case of a bad spark plug, the component fails to perform its primary function which is to provide a spark to ignite the air mixture and fuel ratio.


A bad ignition coil is also among the several reasons for engine misfire. An ignition coil helps with instigating combustion. Engine misfiring is one of the signs of a bad ignition coil in the car.


low fuel pressure is among the engine misfire causes
A lower fuel pressure means the required amount of fuel does not reach the combustion chamber

It is also one of the common reasons for a car engine misfire. In case of low fuel pressure, an inadequate amount of fuel enters the combustion chamber, leading to cylinder misfiring.


A fuel injector ensures the supply of the current amount of fuel to the cylinders. Any damage in the fuel injector leads to an improper fuel supply – eventually leading to a car engine misfire.


Any leaks in the intake manifold gasket can make way for air to enter the combustion chamber. This can disrupt the air-fuel mixture and lead to engine misfire.


bad sensors affect the air-fuel mixture and can lead to a car engine misfire
Bad sensors can affect the air-fuel mixture in the combustion chamber

Modern vehicles come equipped with different types of sensors – each performing a different function. Issues in any of the engine sensors may affect the air-fuel mixture in the combustion chamber.

Car Engine Misfire Symptoms

The aforementioned information sheds light on the causes of engine misfiring. Let’s now take a look at some of the symptoms of car engine misfire.


Rough idle in vehicles is one of the common and first symptoms of an engine misfire. It is also one of the causes of car engine stalling and other problems.


Other than a rough idle, rough acceleration can also indicate an engine misfire. You may also encounter issues like sluggish acceleration than normal.


engine check light can identify problems in the car's engine
A blinking or on engine light usually indicates problems in the engine such as engine misfiring among others

It is another common symptom of a car engine misfire. The check engine light, available in most models, indicates any problems in the engine. If the check engine light turns on or is blinking frequently, it may be because of a misfiring engine.


Different types of engines produce different sounds. For instance, a four-cylinder engine will have a different sound compared to a lower-cylinder engine. In case of a cylinder misfire, you are likely to hear a different sound. This also indicates an engine misfire in cars.


Vibrations in a car can also be an indication of a misfiring engine. If any of the cylinders do not fire properly, the vehicle may experience vibrations. Additionally, a car vibrating when idle may also imply an engine misfiring problem.

How to Fix Car Engine Misfiring Issues

With the causes and symptoms of a car engine misfire now clear, it is equally important to know how to fix these issues. That said, let’s go through some effective ways to fix car misfiring issues.


If the problem lies in the coils or spark plugs, you can easily replace them. Check these components for any signs of wear or damage. Additionally, you can try replacing the coil and spark plug on another cylinder and then check the error codes.

If the other cylinder shows issues, the problem is with the coil or plug. If you encounter any symptoms of a bad spark plug or coil, replace them at the earliest.


use a flammable spray to check the engine for vacuum leaks
Check for vacuum leaks using a flammable spray

Vacuum leaks disrupt the air-fuel mixture in the combustion chamber. Therefore, it is essential to have proper gaskets. One effective way to detect car vacuum leaks is to use a flammable spray.

When the engine is idling, shower the flammable spray on the intake manifold. An increase in engine speed indicates the chamber injecting the spray. Moreover, it is important to keep a fire extinguisher with you while performing this test.

If you are unaware of this, take your vehicle to the service station and let a professional handle the issue. Furthermore, there are some other ways to detect car vacuum leaks effectively.


to a diagnostic test and read codes to identify errors in the car sensors
Mechanics use the codes to indicate any problems in the car’s sensors

Modern car systems monitor and store data received from the sensors. This helps to diagnose the problems in any of the sensors. These codes can be hard to interpret unless you are a professional.

Additionally, you would need proper scanners and a tool kit. Therefore, it is better to have a mechanic check your vehicle for such issues.


Low fuel pressure can also lead to car engine misfires. Therefore, it is important to keep it in check. The process is rather easy and you need to have a fuel pressure gauge. Connect it to the fuel rail and turn on the ignition.

Monitor the fuel pressure on the gauge and compare it to the maker’s specifications. For any disruptions in the fuel pressure, inspect the fuel pump, filter and pressure regulator.

Similarly, you can do a engine compression test on each cylinder to check car cylinder failure. You can either use a leak-down tester or a compression tester to carry out the test.


If the problem persists after you have done engine misfire diagnosis and all the tests, the problem may lie elsewhere. Therefore, it is a viable option to take your vehicle to a mechanic for a specialised inspection. Moreover, if you are not sure about any tests, do not try them on your own. You may end up doing more damage than good.

car mechanics can better solve all issues in a vehicle
It is a viable option to have a professional inspect and resolve any car misfiring and other issues

This is everything about car engine misfire meaning, the causes, symptoms and ways to fix them. A misfiring engine may indicate underlying problems in any of the car’s components. Therefore, it is important to have the issues fixed at the earliest.

Delays can often cause further deterioration and result in bigger expenses. Moreover, keep an eye out for the symptoms of car engine failure to fix any engine-related issues before they turn worse.

Some of the engine components are rather expensive to replace. Therefore, if your car often encounters misfiring issues, it is a considerable option to go for a vehicle change. You can find a plethora of used cars in the UAE as good replacements.

Stay tuned to dubizzle’s auto blog for information about car engine issues and ways to fix them.