What Is an Ignition Coil Pack?

Many modern cars feature ignition coil packs--more commonly known as simply coil packs--as part of the vehicle ignition system. These ignition components help provide motorists a reliable start and uninterrupted operation.

Purpose

  • Ignition coil packs, a modern replacement for distributors, prompt a vehicle's spark plugs to fire. As the plugs fire, the resulting spark ignites fuel in the engine's combustion chamber to power the vehicle.

Appearance

  • When viewing the engine, the ignition coil pack appears metal and cylindrical with a domed top and protruding "tower." The exact size of the coil pack varies from vehicle to vehicle.

Function

  • Ignition coil packs contain two spools of copper wiring. When the vehicle starts, these wires produce a magnetic current that causes a rotating electrical contact to spin. As this contact passes over connected spark plug wires, it sends an electrical signal down the wire to prompt the plug to fire.

Benefits

  • Coil packs replaced carburetors, ignition components that made vehicles difficult to start on cold mornings or after sitting for an extended duration. Because coil packs rely on a magnetic field and electricity, they operate more reliably than their older counterparts.

Considerations

  • Although coil packs provide more reliable operation than carburetors, they do occasionally fail and require replacement.