A car misfire can be an unsettling experience, but luckily it’s usually not something serious. Instead, misfires occur when the spark plugs don’t ignite the air and fuel mixture properly, resulting in a loss of power and potential performance issues. If you experience such problems while driving, here are the four most common causes of car misfires you should be aware of to help identify your problem and get it fixed as soon as possible.
Bad Spark Plugs
The most common cause of a car misfiring is worn or malfunctioning spark plugs. Spark plugs provide the electronic spark necessary to ignite the fuel/air mixture inside the engine’s cylinders. When the spark plugs are not firing correctly, misfires can occur, which lead to knocking sounds, engine stalls, and bad performance. Usually, following the recommended maintenance schedule will prevent issues with spark plugs.
Faulty Ignition Coil
Another common cause of misfires is faulty ignition coils. The ignition coil transforms the low voltage of the car’s battery into the high voltage needed to create a spark inside the spark plug. Many modern vehicles utilize ignition coils rather than a distributor cap. Usually, problems with the ignition coil will trigger a warning light, which may not indicate an issue with the coil. However, malfunctioning ignition coils will need to be replaced as soon as possible.
Flash Over
A buildup of dirt, oil, or moisture on older cars can cause the spark plugs to ground, preventing them from firing correctly. Manufacturers have mostly corrected this on modern vehicles with improved spark plug design; however, flashover still may be possible on some cars. Your mechanic can diagnose this issue and resolve it relatively quickly.
Vacuum Leak
A vacuum leak is when too much air enters the engine’s cylinder(s), causing the air/fuel mixture to become diluted. Vacuum leaks that are confined to one cylinder can cause misfires because the air-to-fuel ratio will be uneven between cylinders. Vacuum leaks can have a few different causes, so it is essential to see a professional to get the cause diagnosed and corrected.
While a misfiring car is not necessarily the most severe issue, it will only worsen if you try to ignore it. So if your vehicle’s engine is misfiring, see your car care professional as soon as possible to get your car’s cylinders firing and your vehicle back to running as it should, trouble-free!