Severe Timing Chain Noise under Various Conditions

05-89121 Severe Timing Chain Noises, When Starting Engine 102.983 Revised 1/90 12/89
a Cold or Warm Engine, at Idle and In Lower
Partial Load Range with Engine at Operating
Temperature





Remedy:
On engine 102.983, install the new check valve chain tensioner, part no. 102 050 08 11. This chain tensioner should also be installed on engines originally equipped with the detent spring chain tensioner.

Tightening torque of check valve chain tensioner in cylinder block: 40 Nm (30 ft. lb.)

Check camshaft sprocket and intermediate sprocket for wear, replace if necessary.

On a tensioning rail with a flat plastic lining, check if the upper edge of the lining is flush with the upper edge of the tensioning rail. If not, the plastic lining came out of the bottom retaining holder or is broken. If necessary, install new tensioning rail (B) with guide rib.