11 31 094 Removing hydraulic chain tensioner for timing chains on left side (N63O1)

Special tools required:

WARNING: Chain tensioner is pre-tensioned.
Release lock pin only in installed state.
Danger of injury!

IMPORTANT: Risk of damage!
The engine must not be cranked when the chain tensioner is removed.
The timing chain may jump.

Necessary preliminary work:

IMPORTANT: The timing chain on the chain tensioner becomes the tight end on cranking back.
Do not turn engine without chain tensioner.

Piston (1) of chain tensioner (2) must be pressed in against oil pressure in housing (see arrow in illustration).

Fig 1: Locating Piston Of Chain Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.

Retract the entire length of the piston of the chain tensioner.

Secure piston with special tool 11 4 120 .

Tightening torque 11 31 5AZ .

Unfasten screws (2 and 3).

Remove chain tensioner (2).

Fig 2: Securing Piston Using Special Tool (11 4 120)

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Danger of injury!
Chain tensioner is under high preload force.

Chain tensioner arrangement:

Pistons
Expansion element
Compression spring
Housing

Fig 3: Exploded View Of Chain Tensioner
Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Replace all gaskets and sealing rings.

Assemble engine.