Valve Train Noise (Loosen & Re-Torque Camshaft Bearing Cap Bolts) (00-T-56)

VALVE TRAIN NOISE

TECHNICAL SERVICE BULLETIN

SUBJECT

Valve Train Noise (Loosen and Re-Torque Camshaft Bearing Cap Bolts).

MODELS AFFECTED

1999 - 2000 Saturn S-Series vehicles built before and including VIN YZ1455976 equipped with DOHC engines (RPO LL0).

CONDITION

Some customers may comment about a light tapping, ticking, or knocking noise that comes from the engine compartment. The frequency of the noise increases with engine RPM. The noise is noticeable when the engine is cold (just started) and after it has warmed up.

CAUSE

A slight misalignment of the intake and/or exhaust camshaft to the camshaft bearings caps may result in a light tapping noise during operation.

CORRECTION

Refer to procedure in this bulletin for vehicle repair.

PROCEDURE

1. Disconnect negative battery cable.
2. Disconnect cam cover air hose at air duct assembly.
3. Remove spark plug wires from spark plugs and cam cover.
   Fig 1: Disconnecting Cam Cover Air Hose Assembly

   
4. Disconnect PCV hose at cam cover.
IMPORTANT: Cover camshaft area whenever repairs are not being performed to prevent foreign debris from entering engine.
5. Remove cam cover bolts and remove cam cover from cylinder head.
IMPORTANT: Do not loosen all camshaft bearing caps at the same time. The camshaft bearing caps must be loosened and re-tightened one at a time.
Fig 2: Loosening Camshaft Bearing Caps

6. Starting at front of engine closest to timing chain gears, loosen and re-tighten each of the intake and exhaust camshaft bearing caps one at a time.
   1. Loosen the camshaft bearing cap bolts of one bearing cap until cap can be moved freely.
   2. Tighten the camshaft bearing cap bolts. Tighten bolts to 14 Nm (10 ft lb).
   3. Repeat steps 6.1 and 6.2 for each of the remaining camshaft bearing caps.
IMPORTANT: Inspect the eight cam cover silicone insulators prior to cam cover installation and replace if damaged or deteriorated.
7. Install cam cover on cylinder head and install bolts. Tighten bolts to 10 Nm (89 in lb).
8. Connect PCV hose at cam cover.
9. Install spark plug wires to cam cover and spark plugs.
10. Connect cam cover air hose at air duct assembly.
11. Connect negative battery cable. Tighten bolts to 17 Nm (13 ft lb).

CLAIM INFORMATION

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as follows:

Case Type	Description	Labor Operation Code	Time
VW	Re-Torque Camshaft Bearing Cap Bolts	Z4128	0.5