Starter Motor: Service and Repair

12 41 020 Removing and installing/replacing starter motor (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.
- Disconnect battery earth lead..
- Remove intake plenum.







Unlock connector (1) and remove.
Unfasten nut.
Tightening torque 12 41 3AZ.
Remove positive battery cable (2).







Release screw (1).

Installation note:
Replace aluminium screws.
Tightening torque 12 41 1AZ.
Unfasten screws (2).

Installation note:
Replace aluminium screws.
Tightening torque 12 41 2AZ.
Remove starter motor (3).







Installation note:
Check starter pinion and ring gear for damage. Replace starter motor if necessary.

N53 only: In the case of a separate Terminal 50 lead (with disconnector socket), the Terminal 50 lead is laid parallel to knock sensor 2 behind the fuel line.