Starter Motor: Service and Repair

12 41 020 - Removing and installing/replacing starter (N52, N52K, N51, N53, N54)





Important!
Aluminium-magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
Aluminium screws/bolts are permitted with and without colour coding (blue).
For reliable identification:
Aluminium screws/bolts are not magnetic.
Jointing torque and angle of rotation must be observed without fail (risk of damage).





Necessary preliminary tasks:
- Switch off ignition
- Clamp off battery negative lead 61 20 900 Disconnecting and Connecting Battery Negative Lead
- Remove intake air manifold Service and Repair





Unlock plug (1) and remove.
Unfasten nut.
Tightening torque 12 41 3AZ 12 41 Starter Motor with Mounting.
Remove battery positive lead (2).





Release screw (1).

Installation Note:
Replace aluminium screws.
Tightening torque 12 41 1AZ 12 41 Starter Motor with Mounting.

Release screws (2).

Installation Note:
Replace aluminium screws.
Tightening torque 12 41 2AZ 12 41 Starter Motor with Mounting.

Remove starter motor (3).





Installation Note:
Check starter pinion and ring gear for damage. Replace starter if necessary.
N53 only: In the case of a separate term. 50 lead (with disconnector socket), the term. 50 lead is laid parallel to knock sensor 2 behind the fuel line.