11 31 090 Installing and removing/replacing chain tensioner piston (N54, N54T)

Necessary preliminary tasks

Remove coolant expansion tank (E89 only)

Release chain tensioner (1).

Tightening torque: 11 31 5AZ .

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 1: Identifying Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

No sealing ring is fitted during series-production assembly.

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

If the chain tensioner is reused, its oil chamber must be drained. Place chain tensioner on a level working surface and slowly compress.

Repeat procedure twice.

Fig 2: Installing Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.