11 31 090 Removing and installing/replacing chain tensioner piston (N57 Diesel)

Necessary preliminary work:

Remove ACOUSTIC COVER .
Remove AIR FILTER HOUSING .

Release chain tensioner (1).

Tightening torque: 11 12 2AZ .

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 into the clutch housing.

Installation note:

Replace sealing ring.

Fig 1: Identifying Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

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

Repeat process twice.

Fig 2: Draining Oil Chamber Of Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.