Astoria Mechanic | Collision Repair | Tolimas Auto Center

Check Engine Light

What are Engine Misfires and Common Causes

One of the most common reasons our customers bring their cars to us is for of excessive engine shaking. This happens when the car is at idle, sitting at a red light. This type of problem tends to be caused by an engine misfire. As the name implies, a misfire occurs when your engine doesn’t get enough air, fuel, or spark into each cylinder. This causes the air and fuel mixture in the problem cylinder[s] to not ignite properly. If the misfire is severe, it will cause a flashing check engine light on your dashboard.

Inside Engine
Combustion and Piston Movement Inside an Engine

Combustion in each cylinder is a violent process that would normally cause a lot of vibration. To prevent that, engineers design engines to have opposing, even number of cylinders. This allows even numbered cylinders to cancel out the vibrations from the odd numbered cylinders going through combustion. If one cylinder is not getting proper air, fuel, or spark then it will misfire. This causes the engine to run off synchronization and shake.

What causes engine misfires?

Spark Plugs and Coils

The most common culprit for an engine misfire tends to be the ignition system. Spark plugs, ignition wires, and coils wear out and fail with age. That is why it is important to have an engine tune up. Worn ignition components will also cause your car to lose horsepower and get poor fuel economy.

Engine Vacuum Leak

Another common cause for engine misfires tend to be vacuum leaks. Your engine computer measures the amount of air coming into your engine. That way it can supply the right amount of fuel for your engine to run efficiently. If you have a vacuum leak then there is un-metered air going into your engine computer won’t know how much fuel to add or subtract. Finding an air leak can be like looking for a needle in a hay stack. The proper way to look for a vacuum leak is with a automotive smoke machine which fill the insides of the engine with smoke. Then our technicians will be able to see where the smoke is coming from to identify the leak.

When you feel excessive vibration from your automobile or see a flashing check engine light on your dashboard, Tolimas Auto Center recommends you have the issue repaired as soon as possible. As driving your car with a misfire can lead to it needing major repairs in the future. When car trouble arises, Tolimas Auto Center is here to help.

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