Back to all

Low Power Mystery (Ignition Coil Service)

April 25, 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.

Tuffy Tire & Auto Service Center Gahanna
115 N. Hamilton Road
Gahanna, Ohio 43230
614-337-8080
http://www.tuffygahanna.com

More articles from Tuffy Gahanna

U and your U-Joints (Lubricate U-Joints)

September 14, 2025

If your vehicles power goes to the rear wheels, then you have something called U-joints in the drivetrain. U-joints are connectors that allow the rotating power from your vehicles engine to deliver its power through a driveshaft to make the rear wheels rotate. You need U-joints because the surfa... More

Getting Off to a Running Start (Starter Replacement)

September 7, 2025

When you start your vehicles engine, theres another motor that makes that whole process possible. Its called the starter, and its a small electric motor that gets your vehicle running. As you can imagine, its quite a chore for a little electric motor to turn over the big engine that powers you... More

No Fueling! (Fuel Filler Location)

August 31, 2025

If you've ever gotten in an unfamiliar vehicle, maybe a rental car, you may have pulled up to the gas pump and wondered, "Which side is the fuel filler on?" Here's a tip for you. There is usually a little arrow on the instrument panel near the fuel gauge that points to the side where the fuel fi... More