BMW X3 (F25) Service & Repair Manual: Starter with mounting

• Handling components after flood damage
• Removing and installing/replacing starter motor (N20, N26)
• Removing and installing/replacing starter motor (N47 D20 O1)
• Removing and installing/replacing starter motor (N52T)
• Removing and installing/replacing starter motor (N55)
• Replacing solenoid switch

Handling components after flood damage

Flood damage can occur if the permissible fording depth of a vehicle is exceeded. Ingress of water can cause damage to the engine (water shock) or components.

Because dirt particles generally enter into the component with the water (e.g. starter motor, wiring harness), the components need to be thoroughly inspected.

Residual moisture in the components leads to corrosion (increased contact resistance in the component), which can lead to a component failure at a later time.

If water ingress into the electrical components cannot be ruled out, it is recommended to replace the component to ensure correct functioning through the vehicle lifetime.

Removing and installing/replacing starter motor (N20, N26)

Necessary preliminary tasks:

• Switch off ignition.
• Disconnect BATTERY NEGATIVE LEAD .
• Remove INTAKE PLENUM .

Unlock connector (1) and remove.

Release nuts (2) and disconnect positive battery cables.

Release screws (3).

Feed out starter motor and remove.

Installation note:

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

Only during starter replacement and on vehicles with MSA (automatic engine start-stop function):

• Use BMW diagnosis system to reset the starter counter.

Removing and installing/replacing starter motor (N47 D20 O1)

Necessary preliminary tasks:

• Switch off ignition.
• Disconnect BATTERY NEGATIVE LEAD .
• Remove REINFORCEMENT PLATE .

Release nut (1) and remove cable.

Release nut (2) and remove the positive battery cable.

Release cable at clamp (3) from starter motor.

Release screws (1), (2) and (3).

Remove starter motor.

Installation note:

Observe screwing sequence.

Position and secure starter motor. Tighten down screws (1) and (2). Tighten down support screw (3).

Installation note:

Check starter pinion and ring gear for damage.

Replace damaged starter motor.

Assemble engine.

Only during starter replacement and on vehicles with MSA (automatic engine start-stop function):

• Use BMW diagnosis system to reset the starter counter.

Removing and installing/replacing starter motor (N52T)

IMPORTANT: Aluminum-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 .

Aluminum screws/bolts are permitted with and without color coding (blue).

For reliable identification: Aluminum 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 NEGATIVE LEAD .
• Remove INTAKE PLENUM .

Unlock connector (1) and remove.

Unfasten nut.

Remove positive battery cable (2).

Release screw (1).

Installation note:

Replace aluminum screws.

Unfasten screws (2).

Installation note:

Replace aluminum screws.

Remove starter motor (3).

Installation note:

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

Assemble engine.

Only during starter replacement and on vehicles with MSA (automatic engine start-stop function):

• Use BMW diagnosis system to reset the starter counter.

Removing and installing/replacing starter motor (N55)

Necessary preliminary tasks:

• Switch off ignition.
• Disconnect BATTERY NEGATIVE LEAD .
• Remove INTAKE PLENUM .

Unlock connector (1) and remove.

Release nuts (2) and disconnect positive battery cables.

Release screws (3).

Remove starter motor (4).

Installation note:

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

Only during starter replacement and on vehicles with MSA (automatic engine start-stop function):

• Use BMW diagnosis system to reset the starter counter.

Replacing solenoid switch

Turn off ignition.

Release nut (1).

Remove cable lug (2).

CAUTION: Do not turn cable lug (2) while tightening down - risk of short circuit to starter motor housing.

Release screws (1).

Remove solenoid switch (1) and spring (2).

Unhook pin (3).

Installation: Check pin (3) for wear and apply grease.