Ignition coils make it possible for spark plugs to generate the sparks that ignite air-fuel mixture that powers the internal combustion engine. Ignition coils transform low voltage from the car battery into high voltage that spark plugs require to generate the sparks.

Over time, ignition coils may fail. When the ignition coil starts to fail, you may notice a number of behaviors that are not typical for your vehicle. You may notice that the check engine light came “on”, or that there is loss of power, or slow acceleration. Engine may run poorly, it may misfire, or it may even stall.

These are all symptoms that indicate something is seriously wrong – but it takes a professional mechanic with professional diagnostic tools and skills to track down all the possibilities and get to the root cause of the problem. If it turns out that ignition coil is at fault, ignition coil replacement will fix the problem. Generally we recommend replacing all ignition coils at the same time, even if only one is causing problems – chances are others are not far behind.

We do not recommend driving around with failing ignition coils as it can be dangerous if the car stalls in the middle of an intersection. Driving around with failed ignition coil(s) can also result in catalytic converter damage, and replacing catalytic converter is an expensive repair.

As with any critical system repair, we recommend visiting a shop you trust, preferably one that employs ASE certified technicians. Your vehicle may never require ignition coil replacement, but we recommend caution if your vehicle exhibits the symptoms we listed above. Even if they are not due to ignition coils going bad, they are serious enough to warrant a visit to your friendly auto repair shop.

You can find local trusted auto repair shops elsewhere on the Nor Cal Auto Talk site.