Oil Pump: Service and Repair

11 41 000 Removing And Installing/Replacing Oil Pump (N74)

Special tools required:







IMPORTANT:
All the adjustment operations on the chain drive must be observed.
A timing chain which is tensioned too tautly can cause noises in the chain drive.
A timing chain that is too slack can cause the timing chain to jump.
Risk of damage in oil pump drive.







Necessary preliminary tasks:
- Drain engine oil.
- Remove upper oil sump section.







Unscrew nuts (2).
Tightening torque: 11 41 1 AZ.
Remove intake pipe (1).

Installation note:
Replace O-ring.







Release all nuts (1) using special tool 11 7 201.
Tightening torque 11 41 7AZ.
Remove oil pump drive gear.

NOTE: Picture shows engine removed.







Unscrew nuts (1).
Tightening torque 11 41 4AZ.







Release screw (1).
Tightening torque 11 41 4AZ.







Detach oil lines (1) upwards in direction of arrow.







Installation note:
Replace sealing rings (1).

Apply light coat of oil to sealing ring (1).
Coat sealing ring (2) with suitable lubricant.







Installation note:
Replace O-ring (1) for oil feed line.







Fit oil lines (1) in direction of arrow.







Installation note:
If the oil pump is replaced, it will be necessary to modify the oil deflector.

Release screws (1).
Tightening torque: 11 41 2 AZ.
Modify oil deflector (2).

NOTE: Graphic shows N63.







Fit special tool 11 8 920 on special tool 11 9 280.







IMPORTANT:
Left-hand thread on oil pump screw connection.
Do not grip oil pump drive with a pair of pliers risk of damage.







IMPORTANT: Nut (1) has left-hand thread.

Position special tool 11 8 920 on sprocket.
Slacken nut (1).







Installation note:
Check mounting flats on pump shaft (1) for damage.







IMPORTANT: Nut (1) has left-hand thread.

Grip pump with assistance of a second person.
Secure nut (1) with special tool 00 9 120.
Tightening torque: 11 41 6 AZ.







Join and secure nuts (1).
Tightening torque 11 41 4AZ.







Install oil pump drive gear.
Secure all nuts (1) with special tool 11 7 201.
Tightening torque 11 41 7AZ.







Adjust oil pump timing chain.
Pretension oil pump adjusting sleeve (1) with a hexagon socket wrench.
Adjustment value 9 mm ±2.







Procedure on removed engine:
Upper oil sump has been removed.

Minimally preload timing chain (1) with special tool 51 0 342.
Read off measured value A on special tool 51 0 342 and note down.

IMPORTANT: Do not use force to preload timing chain (1).







Using a screwdriver (1), preload timing chain to minimal extent in direction of arrow.
Read off measured value B on special tool 51 0 342 and note down.

IMPORTANT: Do not use force preload timing chain.

Measured value A minus measured value B results in the adjustment value.
Adjustment value 9 mm ±2.







Procedure on installed engine:
Upper oil sump has been installed.

Position drag pointer (1) of special tool 2 213 485 on oil pump chain.







Installation note:
Attachment point (1) N63 / S63.
Attachment point (2) N74.







IMPORTANT: Do not use force preload timing chain.

Push drag pointer (1) to the left and right until value has been determined.
Adjustment value 9 mm ±2.







Adjust oil pump timing chain.
Pretension oil pump adjusting sleeve (1) with a hexagon socket wrench.
Adjustment value 9 mm ±2.







Join and secure screw (2).
Tightening torque 11 41 4AZ.







Assemble engine.