BMW 7 Series: Removing Hydraulic Chain Tensioner For Timing Chains On Left Side (N63)

Notes

WARNING: Chain tensioner is pre-tensioned.

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

• Remove TIMING CASE COVER at top left

Crank engine back at central bolt (1) against direction of engine rotation by approx. 90º.

Fig. 268: Cranking Engine Back At Central Bolt Against Direction Of Engine Rotation By Approx. 90º

IMPORTANT: The timing chain on the chain tensioner becomes the tight end on cranking back.

Do not crank engine without chain tensioner or special tool 11 9 900.

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

Fig. 269: Identifying Piston Of Chain Tensioner Pressed In Against Oil Pressure In Housing

If the chain tensioner piston is retracted over its full length, a 3.5 mm drill bit or a suitable lock pin must be positioned.

Fig. 270: Identifying Chain Tensioner Piston Retracted Over Its Full Length

Release screws (1).

Tightening torque 11 31 5AZ.

Remove chain tensioner (2).

Fig. 271: Identifying Chain Tensioner And Screws

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

Chain tensioner arrangement:

• Piston
• Expansion element
• Compression spring
• Housing

Fig. 272: Identifying Chain Tensioner Arrangement

Installation note:

Replace all gaskets and sealing rings

Assemble engine.

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