Engine Electrical
Ignition Coil
An ignition coil turns battery voltage into the high voltage that fires your spark plugs. We carry 137 ignition coils from $11 to $522 for engines from 1984-2025, from TRQ, Standard Motor Products, NGK and MSD, with fits for the Ford Expedition and Escape, Ram 1500 and 2500, Dodge Dakota and Silverado 2500 HD.
Shop ignition coil by vehicle
Signs of a failing coil
A weak or failed coil causes misfires, which you may feel as a stumble under load, a rough idle or a loss of power. The check engine light may flash during a misfire, and a misfire code often points to one cylinder.
On coil on plug engines, you can swap the suspect coil with one from another cylinder. If the misfire moves with the coil, the coil is the problem.
Coil types and sets
Older engines use one coil feeding a distributor. Many later engines use a coil pack serving pairs of cylinders, or a coil on each plug. Some listings here are single coils, while others are sets of 2, 6, 8 or 12 pieces. Some kits pair coils with spark plugs or with an ignition control module.
Replacing a full set makes sense on high mileage engines where the other coils are the same age.
Fitment and install tips
Match the engine size, year and coil design from the fitment table, and compare the connector and part number. Resistance specs vary, so do not mix coils from different systems.
Disconnect the battery before you start. Inspect plug boots for cracks and carbon tracks, and apply a light coat of dielectric grease inside new boots if the maker recommends it. Replace worn spark plugs at the same time.
Ignition Coil questions
Should I replace all ignition coils at once?
If one coil failed on a high mileage engine, the others may be near the end too. Many owners replace the set. On a newer engine, replacing the single failed coil is common.
Can a bad spark plug damage an ignition coil?
Yes. Worn plugs need higher voltage to fire, which strains the coil. Replace old plugs when you replace coils. Check the plug gap on new plugs before you fit them, and inspect the coil boots for cracks.
How do I find which ignition coil is bad?
Read the misfire code with a scan tool, then swap the suspect coil to another cylinder. If the misfire follows the coil, replace that coil.