Ignition coil: common defects and their signs

1. Overheating
   • Troubles occur during engine start, sometimes it doesn’t start at all.
   • Engine operation is unstable at idling.
   • Engine power lowered and fuel consumption increased.
2. Short circuit in winding
   • Engine operation is unstable, especially in cold or moist weather.
   • “Check Engine” indicator activates on the dashboard.
   • Failures in engine operation occur at sharp accelerator pedal pressing.

How to repair ignition coil?

If the part is broken down it should be replaced immediately. Driving with a defective ignition coil may lead to engine overheating, which is quite negative for the car. Replacement of the ignition coil can be performed by your own, but only if car servicing works experience is present. Otherwise it is better to contact a service station. The component replacement algorithm is following:

1. Turn off ignition and wait for the engine to cool down.
2. Cut off power supply from the battery.
3. Disconnect the wires coming to the ignition coil from it. Remember or mark their position, in order to avoid mistakes at installation.
4. Unscrew the nuts fastening the coil, pull it and remove from the housing.
5. Install a new component, fix it with the help of nuts and connect the wires.
6. Mount the negative terminal to the battery.

Turn off the ignition in the car before servicing.
Disconnect the cable from the negative terminal of the battery.
Carefully inspect spark plugs, their wells and terminals while replacing the ignition coil.
Use special tools to keep the replacement of the ignition coil convenient and safe.
Try to remove the part carefully in order to avoid damaging the ignition coil plug.
Average service life: 110 000–140 000 km.

Kinds:

1. By design:
   • common ignition coils;
   • single lead ignition coils;
   • dual lead ignition coils.