11 31 090 Removing and installing/replacing chain tensioner piston (N55 hybrid)

WARNING: Compliance with the following points is mandatory before beginning work:

Observe SAFETY INFORMATION for working with electric vehicles.

Necessary preliminary work:

Release EXPANSION TANK and place to one side.

Release chain tensioner (1).

Tightening torque 11 31 7AZ .

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

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: Compressing Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.