Low Power Mystery (Ignition Coil Service)
February 16, 2020
It's no fun when your vehicle just doesn't run the way it used to. You may notice (especially in cold weather) the engine won't start easily or when it does start, it doesn't run smoothly. It may not have much power at all. You also may have had to stop at the gas station more often, a sign your fuel economy isn't what it used to be.
There could be a few different things that cause those symptoms, but one culprit could be a bad ignition coil. The coil takes the voltage from your battery and multiplies it before that power is sent over to a spark plug. That allows the plug to fire off a good jolt of electricity that ignites the fuel in your cylinder and powers the engine.
There's usually one ignition coil for each cylinder (or sometimes for a pair of cylinders). If only one of them is not pushing out enough electricity, it can cause big trouble with your engine performance. Other signs of a bad ignition coil include engine backfire, an oil leak and your Check Engine light coming on. When that light comes on and you have some of those other signs, you need to have your repair facility check things out fairly soon because you may be damaging your engine and wind up with a far more expensive repair.
A technician will check for a computer code to pinpoint which cylinder is having the problem. Using other diagnostics, the technician can rule out other components that might be causing the engine to misfire. Ignition coils usually last 100,000 miles/160,000 km, but other engine conditions can cause them to fail before then.
Your service advisor may suggest getting all your coils replaced even though only one is malfunctioning. That's probably a good idea in a higher mileage vehicle since the other coils may be close to failure, too. It's also wise to do that if your vehicle's coils are located in a hard-to-reach spot so you likely won't have to spend the money for that labor again when another one fails.
Auto Lab Troy
2790 West Maple Rd.
Troy, Michigan 48084
(248) 643-7690
Need Service?
More articles from Auto Lab Troy
The Untold Truth About Blinker Fluid: Why Your Car Desperately Needs It
May 10, 2026
If youve been ignoring your dashboard, your mechanic, and that one guy at the gas station who muttered bro your blinkers sound dry, then buckle up because today we dive into the critical world of blinker fluid maintenance. What Is Blinker Fluid? Blinker fluid is a high-viscosity, luminescent com... More
No Charge (Why Won’t My Battery Hold a Charge?)
April 15, 2026
When your vehicles battery is dead, it leaves you with that horrible, helpless feeling. A dead battery means it wont hold a charge, and there are several reasons it wont. One is age. Batteries have chemical and electrical systems in them that create power, and as time goes by, they wont work we... More
In the Red (Why a Vehicle Overheats)
April 14, 2026
Heat is one thing that can damage a vehicle, especially if a problem isnt taken care of soon. Be on the lookout for signs that its getting too hot in some parts of your vehicle, starting with the most obvious one: the heat gauge/warning light on your instrument panel. When you see that heat gaug... More