BMW X3 Service & Repair Manual: Replacing ignition coils (N20)

Necessary preliminary tasks:

• Read out the fault memory of the DME control unit.
• Check stored fault messages and process procedure.
• Switch off ignition.
• Remove ACOUSTIC COVER

IMPORTANT: Ignition coils must not be contaminated by fuel.

The resistance of the silicone material is reduced significantly by contact with fuel, which may cause the ignition coil to fail! The silicone tube of the spark plug connector is coated with talc to reduce the pulling forces.

The silicone tube must NOT be oiled or greased. This would greatly reduce the durability of the silicone material, which can lead to a malfunction of the ignition coil.

Unlock plug catch (1) of ignition coil (2) and disconnect plug.

Ensure that cables are not crushed or damaged.

Repair damaged cable.

Pull ignition coil (2) up and out.

NOTE: There is a possibility that the silicone tube will tear and therefore be destroyed.

This procedure is applicable to all ignition coils.

Installation note:

Position the ignition coil and gently push it to the limit position, if necessary by twisting it back and forth slightly. Then check anti-twist lock.

The rubber cap must completely surround the sealing collar of the cylinder head cover.

NOTE: If rubber parts are squashed, the ignition coil can slip out again during engine operation.

Push connector (1) with connector catch (2) open onto ignition coil.

The connector must be positioned on the counter piece with hardly any gaps when the locking lever is being closed. In the process, the cheeks of the lever are positioned inside the counter piece.

NOTE: The locking lever can become deformed if it is not installed correctly. This means that there is no longer a safety lock on the plug connection. As a result, the connector can slip out during engine operation (loose contact, misfiring).

Assemble engine.