11 31 090 Installing and removing or replacing chain tensioner piston (N18)

Special tools required:

11 9 590

Necessary preliminary tasks:

Remove WHEEL ARCH SHELL AT FRONT RIGHT .

IMPORTANT: Risk of chain jumping.
Position engine in 90° position with special tool 11 9 590 .
Balance hole and dowel hole can be mixed up.
If necessary, determine by means of spark plug bore.

Fig 1: Securing Crankshaft Using Special Tool (11 9 590)

Courtesy of BMW OF NORTH AMERICA, INC.

Rotate crankshaft at central bolt.

Position crankshaft with special tool 11 9 590 .

Release chain tensioner (1).

Tightening torque: 11 31 4AZ .

IMPORTANT: Have a cleaning cloth ready. A small quantity of engine oil will emerge after the screw connection has been released.
Make sure no oil runs onto the belt drive.

Fig 2: Identifying Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

A new sealing ring must be installed by service personnel when the chain tensioner is fitted.

Remove all special tools.

Assemble engine.