An engine misfire happens when the cylinders in the engine don’t burn right or the combustion within the chamber is incomplete. Typically, engine misfires can be caused by a variety of factors, including malfunctioning coils, worn or faulty spark plugs, a leak or a faulty ignition switch. 

Here are some of the more common causes of engine misfires 

Common Signs of an Engine Misfire

Ignition Trouble

In many cases, a worn-out spark plug is to blame for an engine misfire. Spark plugs play a key role in igniting the fuel in the engine. When a spark plug is worn out or bad this process cannot take place, leading to engine misfires. 

It’s also important to keep in mind, however, that spark plugs are only one piece of the larger ignition system. Issues with any components — coil packs, wiring, control module, etc. — within the ignition system can cause an engine misfire. 

Mechanical Error

Another cause of a misfire may be due to mechanical failure within the engine. Issues with components of the engine that keep the cylinders from sealing properly can lead to poor compression and poor burn, thus resulting in an engine misfire. 

Emissions Equipment Problems

Engines have a specific air/fuel mixture that is crucial for combustion. Most modern vehicles have complex equipment meant to release exhaust and emissions, the result of combustion, back into the atmosphere. If this equipment malfunctions and leaves emissions in the engine, it can mess with the air/fuel mixture, leading to a misfire.

Diagnosing An Engine Misfire

All this information about engine misfires isn’t actually helpful unless you’re able to tell when a problem is occurring. 

What Does an Engine Misfire Feel Like?

An engine misfire can feel slightly different depending on the type of problem occurring. Generally speaking, though, some of the most common signs of a misfire is hesitation or loss of power during acceleration. 

When you first turn your car on or once you start moving after common to a stop at a light you may notice that your vehicle is having a rough time idle. If your engine is unbalanced as a result of a misfiring cylinder you may experience shaking. 

What Does an Engine Misfire Sound Like?

Another way to diagnose an engine misfire is by sound. Engine misfires have a very distinct sound that can make them easier to diagnose than other car problems. 

Popping, sneezing, or banging sounds coming from the exhaust are a sign of a misfire. This sound comes from the unburnt fuel leaving the cylinder that combusts through the exhaust system. 

What are the Dangers of Engine Misfire?

Engine misfires can lead to huge problems if not addressed quickly. Any of the causes of a misfire can have drastic consequences and can cause irreversible damage to an engine and catalytic converter (we discuss the importance of your catalytic converter in this previous blog post)


If you think your engine is misfiring, don’t delay in getting it looked at as soon as possible. Request an appointment with our team at Beetlesmith’s Valley Auto Service in Renton today!    

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