Auto Systems and Repair: Ignition Coil

Symptoms of Wear or Failure

  • The Check Engine Light may come on
  • The engine may run rough or stall
  • Lack of power on acceleration
  • The engine cranks, but will not start

Related Repair Advice

  • Continuing to drive with the above mentioned symptoms can damage the catalytic converter
  • An engine can have a single ignition coil that covers all cylinders; one coil for each cylinder head of a V6 or V8 engine; one coil for every two cylinders (waste spark ignition); or one coil for each cylinder in the engine (coil-on-plug ignition)
  • On some vehicles, it may be necessary to remove the intake manifold to gain access to the ignition coils
  • A failed ignition coil can be the result of failures elsewhere in the ignition system. The ignition wires and spark plugs should be inspected and replaced if necessary.
  • Oil or coolant leaks can damage ignition coils—the leaks need to be repaired along with the ignition coil
  • Care should be taken when servicing the ignition system as up to 45,000 volts may be present while the engine is running