BMW X5: Alternator With Drive
REPLACING ALTERNATOR BELT PULLEY
Special tools required:
- 12 7 110.
Remove and install alternator drive belt.
Depending on alternator type, grip shaft with:
- hexagon socket
- multi-tooth socket or
- Torx socket wrench
Release nut with special tool 12 7 110.
Installation:
Tightening torque, 12 31 2AZ / 12 31 3AZ.
.png)
Fig. 30: Identifying Special Tool (12 7 110)
REPLACING ALTERNATOR BELT PULLEY (WITH OVERRUNNING CLUTCH)
Special tools required:
- 12 7 120
Remove and install alternator drive belt.
Grip alternator shaft with:
- internal serration
Release nut with special tools 12 7 120.
Installation:
Tighten to specified torque.
CHECKING ALTERNATOR (BSD)
Necessary preliminary tasks:
- Correct connections on charged battery
- Correct connections on alternator and starter motor
- Good ground connection between engine and body
- Tensioned ribbed V-belt
- Read out DME/DDE fault memory.
NOTE: The alternator with BSD interface can communicate with the engine control unit (DME/DDE).
The alternator is not connected to the charge telltale light.
The alternator can identify various faults.
BSD alternator can be recognized by the plug connection on the alternator.
Connect diagnosis tester.
- Function selection
- Complete vehicle
- Drive
- Voltage and current regulation
- Voltage and current generation
- Alternator
- Follow instruction in diagnostic program
Oscillogram for a fault-free alternator:
.png)
Fig. 31: Wave Form Graph - Fault-Free Alternator
Oscillogram for a faulty alternator:
One phase interrupted.
Repair/exchange alternator.
.png)
Fig. 32: Wave Form Graph - One Phase Interrupted
Interturn fault.
Repair/exchange alternator.
.png)
Fig. 33: Wave Form Graph - Interturn Fault
Open circuit in negative diode.
Repair/exchange alternator.
.png)
Fig. 34: Wave Form Graph - Open Circuit In Negative Diode
Short circuit in positive diode.
Repair/exchange alternator.
.png)
Fig. 35: Wave Form Graph - Short Circuit In Positive Diode
Open circuit in positive diode.
Repair/exchange alternator.
.png)
Fig. 36: Wave Form Graph - Open Circuit In Positive Diode
Open circuit in exciter diode.
Repair/exchange alternator.
.png)
Fig. 37: Wave Form Graph - Open Circuit In Exciter Diode
Assemble engine.
Check function of DME/DDE.
REMOVING AND INSTALLING OR REPLACING ALTERNATOR (N52K)
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.
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 alternator drive belt.
Unlock plug (1) and remove.
Slacken nut (2).
Installation:
Tightening torque 12 31 1AZ.
Release screws and remove alternator (3).
.png)
Fig. 38: Identifying Alternator Plug And Nut
Installation:
Replace aluminum screws.
Tightening torque 12 31 1AZ.
.png)
Fig. 39: Identifying Alternator Guide Pulley
READ NEXT:
Regulator
REPLACING VOLTAGE REGULATOR
Necessary preliminary tasks:
Switch off ignition
Disconnect battery negative lead.
Notes on removing and installing electronic control units.
Remove alternator
Bosch:
Starter With Mounting
REMOVING AND INSTALLING/REPLACING STARTER MOTOR (N52, N52K, N51, N53,
N54)
IMPORTANT: Aluminum-magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical
corrosion.
Starter Lead
REMOVING AND INSTALLING OR REPLACING BATTERY POSITIVE LEAD
(BETWEEN STARTER, ALTERNATOR AND BATTERY POSITIVE TERMINAL)
Necessary preliminary tasks:
Read out fault memory of DME control unit; if nece
SEE MORE:
Crankcase Ventilation
One of the major changes on the new NG6 engines is that the crankcase
ventilation system has been upgraded
and improved. This applies to all of the new NG6 versions (N52KP, N51 and N54).
There are two distinct versions of crankcase ventilation. One type is unique to
the N54 and the other applies
Performance Controls
Cooling System
The cooling system of the N54 engine consists of a radiator circuit and an
isolated oil cooling circuit. The fact
that there is an isolated oil-cooling circuit ensures that heat is not
introduced via the engine oil into the engine's
coolant system.
Fig. 71: Identifying Cooling S
