Back to all

Low Power Mystery (Ignition Coil Service)

November 28, 2021

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.

Courtesy Auto Repair Plus
967 Bon Air Ave
Tiffin, Ohio 44883
419-443-0797
http://www.courtesyautorepairplus.com

More articles from Courtesy Auto Repair Plus

Taking the Heat (Batteries in Hot Weather)

May 24, 2026

Quick question. Which is tougher on a vehicle's battery, the heat or the cold? Believe it or not, it's the heat. Think about it. The battery often sits in the engine compartment next to that motor generating lots of heat. That can accelerate corrosion in the battery and may even cause water i... More

Why People in Tiffin Hesitate to Get Their Vehicle Serviced

May 17, 2026

A recent report stated that over 80 percent of the vehicles on our Tiffin, Ohio, roads have one or more service or repair that's needed but hasn't been taken care of. Now that's a lot of undone service. That translates into something over 160 million vehicles in North America alone. Some of the n... More

Hitting The Brakes In Tiffin

May 10, 2026

Hello Tiffin, let's talk about brakes. But the mechanical aspects of the brakes themselves are just one issue. There's also the power brake pump and brake fluid. And then there are the tires, which are critical to the effectiveness of the brakes.Let's step back. A new vehicle or truck rolls of... More