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 aluminum screws/bolts exclusively.
Aluminum screws/bolts must be replaced each time they are released.
The end faces of aluminum screws/bolts are painted blue for the purposes of reliable identification.
Jointing torque and angle of rotation must be observed without fail (risk of damage).

Necessary preliminary tasks:

Switch off ignition
Disconnect battery negative lead
Remove INTAKE AIR MANIFOLD

Unlock plug (1) and remove. Unfasten nut.

Tightening torque 12 41 3AZ .

Remove battery positive lead (2).

Fig 1: Identifying Battery Positive Lead And Plug

Courtesy of BMW OF NORTH AMERICA, INC.

Release screw (1).

Installation:

Replace aluminum screws.

Tightening torque 12 41 1AZ .

Release screws (2).

Installation:

Replace aluminum screws.

Tightening torque 12 41 2AZ .

Remove starter motor (3).

Fig 2: Identifying Starter Motor And Screw

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Check starter pinion and ring gear for damage, replace starter motor 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.