Engine ignition coils eventually require repair or replacement just like nearly every other vehicle component. The question is when repair or replacement is necessary. Furthermore, most drivers are unaware of the types of clues their vehicle will provide indicating the time is right for this essential work. Let’s take a quick look at the top signs that indicate your vehicle’s ignition coils need immediate attention.

Reduced Fuel Efficiency

If you notice a reduction in your vehicle’s fuel economy, it can indicate a failing ignition coil. A compromised ignition coil has the potential to cause the vehicle to consume more fuel. This heightened consumption occurs to offset the insufficient power transfer between the spark plugs and battery. When in doubt, be safe rather than sorry by inspecting the ignition coil for damage as soon as you notice a reduction in fuel efficiency.

The Vehicle Does not Start or Stalls After Starting

An ignition coil that no longer works might prevent the vehicle from starting. A faulty ignition coil can also cause the vehicle to stall after it has started. If your vehicle will not start and the ignition coil is the true problem, the spark plugs are not being provided with the necessary amount of charge from the vehicle battery. Replace the faulty ignition coil(s) and your vehicle will start as it should, providing uninterrupted operation across posterity, ensuring you and your riders are as safe as possible.


If you notice the odor of gasoline when you start your car or if you spot black smoke coming out of the exhaust, the vehicle is backfiring. Backfiring means the vehicle is releasing unused gasoline by way of the exhaust system. It is possible the ignition coil is either worn or faulty. Do not assume backfiring is merely an aesthetic issue. The truth is backfiring has the potential to compromise your safety. When in doubt, replace the ignition coil to ensure you and your vehicle occupants are safe rather than sorry.

The Check Engine Dashboard Light is Illuminated

If the check engine warning light illuminates on the dashboard, there might be a problem with one or more of your vehicle’s ignition coils. However, there might also be multiple mechanical issues with the engine. It is quite possible the ignition coil is one of several potential problems that an experienced mechanic can accurately identify.

A Misfiring Engine

A misfiring engine is problematic in that it can lead to:

  • The loss of power
  • Uncomfortable vibrations
  • Reduced fuel efficiency
  • A bumpy driving/riding experience

Furthermore, if your car feels like it is on the brink of stalling or beginning to break down, there is a chance the ignition coil is the underlying problem.

The Engine Does not Accelerate as It Should

If the engine ignition coil is faulty, your vehicle will likely struggle to accelerate as it should. However, there is also the chance that a faulty injector is the true problem.

Excessive Emissions

A malfunctioning ignition coil is likely to boost vehicle emissions. In particular, the vehicle’s hydrocarbon emissions are likely to increase. California and Nevada are examples of two states with strict emissions testing standards. It is quite possible your vehicle will fail these mandatory tests due to a faulty ignition coil so be sure to address the problem sooner rather than later.