11 31 090 Installing and removing/replacing chain tensioner piston (N14)
Special tools required: 11 9 590
Necessary preliminary tasks: Remove wheel arch shell at front right. See 51 71 040 REMOVING AND INSTALLING/REPLACING FRONT LEFT OR RIGHT WHEEL ARCH COVER (R57) , 51 71 040 REMOVING AND INSTALLING/REPLACING FRONT LEFT OR RIGHT WHEEL ARCH COVER (R56) or 51 71 040 REMOVING AND INSTALLING/REPLACING FRONT LEFT OR RIGHT WHEEL ARCH COVER (R55) . Remove intake silencer housing. See 13 71 000 REMOVING AND INSTALLING/REPLACING THE INTAKE SILENCER HOUSING (N14)
Danger of chain jumping at camshaft sprockets.
To avoid: turn crankshaft at central bolt until crankshaft drive (flywheel) is positioned with special tool 11 9 590 and blocked.
Release hose clamps (1) and detach charge air hose (2).
Installation note:
Install charge air hose (2) dry and free from grease.
Connecting branch on throttle valve must be dry and free from grease.
Position hose clamps (1) again correctly and ensure sufficient spacing to adjacent components.
The spacing between hose clamp and brake line must be 15 mm.
Release chain tensioner (1).
Tightening torque 11 31 4AZ
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.
Installation note:
A new sealing ring must be installed by service personnel when the chain tensioner is fitted.
Remove all special tools.
Assemble engine.