The topic of ignition coils really gets us fired up. As a crucial component of your vehicle’s ignition system, their health is directly linked to the performance of your spark plugs and, therefore, your engine. In fact, without properly functioning ignition coils, your engine may not run well or start at all. Read on to learn how ignition coils work and signs that yours may have failed.

WHAT ARE IGNITION COILS?

An engine needs four things to run — air, fuel, compression, and spark. Ignition coils take care of the “spark” part, delivering as much as 60,000 volts of power to your vehicle’s spark plugs. How they do this is nothing short of magic.

By opening and closing a circuit in the primary winding of copper wire in the coil, a magnetic field across those windings collapses. Every time the magnetic field collapses, a momentary voltage spike occurs. This effectively increases 12-volt car battery power to a few hundred volts in the primary windings and tens of thousands in the secondary windings that the spark plugs need to operate.

On older vehicles, a distributor was used to take power from a single coil and distribute it to each spark plug at the correct intervals. While effective for the time, this single coil setup wasn’t as accurate or powerful as the coil-on-plug (COP) design cars use today.

In COP setups, a distributor isn’t necessary to split a single coil’s energy. Instead, each spark plug typically has its own designated ignition coil, and a computer uses various sensors to determine how much power the spark plugs need and when they should fire.

HOW LONG DO IGNITION COILS LAST?

Ignition coils generally last 80,000 to 100,000 miles. However, as with most vehicle components, certain conditions like the ones below may cause them to fail sooner.