Are Your Car's Ignition Coils Failing?


Every internal combustion engine requires a spark to ignite the air/fuel mixture in the engine's combustion chambers. Automakers have used various methods for ignition over the years, although many cars now use a coil-on-plug design. This engineering approach uses a separate ignition coil for each cylinder, allowing for tighter computer control and better overall reliability.

However, ignition coils are not immune to failure. Like any other part on your car, they can wear out through use, as a result of other engine problems, or due to manufacturer defects. While a coil failure won't usually cause additional damage to your car, it's worth understanding the symptoms of a faulty coil to keep your car running at peak performance.

Understanding How Faulty Coils Affect Your Engine

Ignition coils have two jobs:

  • Convert low voltage to high voltage
  • Send that high voltage to your spark plugs to trigger ignition

Your engine relies on precise ignition timing, so your coils must react immediately to control signals from the ignition control module. A faulty coil may fail to consistently or reliably send the appropriate voltage to your spark plugs, resulting in delayed or failed ignition. When the problem becomes severe enough, it will create noticeable misfires in your engine.

Recognizing the Signs of Failing Ignition Coils

A failed ignition coil or one that is severely underperforming will usually create some highly apparent symptoms. You might notice your car idling roughly or feel a severe lack of power and hesitation when accelerating. These problems usually mean your engine is experiencing a consistent misfire, and you'll typically also see a flashing check engine light.

The early signs might be slightly more subtle and often overlap with other potential problems. For example, you might feel a slight lack of power, have reduced fuel economy, or notice your car taking longer to start in the morning. These problems might indicate a problem with an ignition coil, but they can also point to many other issues.

Repairing Your Failing Ignition Coil

The good news is that an experienced auto repair shop should be able to diagnose ignition coil problems relatively quickly. The coils are generally fairly easy to access on most cars, and a technician can narrow down the specific coil at fault by removing or swapping coils and looking for changes in your engine's behavior.

Since a failing ignition coil won't necessarily produce a check engine light immediately, you may want to consider having a shop diagnose any noticeable changes in your car's behavior, including hesitation or reduced fuel economy. Checking on these problems can help you resolve the issue before your car begins seriously misfiring, helping you avoid many more severe symptoms of coil failure.

Visit a local auto repair shop to learn more.


20 June 2023

maintaining the brakes on your car

When is the last time you had your brakes checked? Are you waiting until you hear the brake pads grinding into the rotors before you do anything to replace them? Does your car pull to one side when you press on the brakes? Do you feel a shimmying in your steering wheel and brake pedal as you press the pedal to stop? If you have any of these issues, it is time for you to learn how to care for the brakes on your car effectively. Taking preventative measures and getting repair work done before serious problems arise will save you money over the years.