Engine - Tapping/Rattling Noises

No: 12/02/00/NAS

Ref: WSM Section 12
Overhaul Manual

Replaces TIB 12/01/98/NAS

Issue: 2

Date: 12/22/00

Rocker Arm Rattle/Tapping Sound

AFFECTED VEHICLE RANGE:
RANGE ROVER (LP) WA382672 to YA437311
DISCOVERY SERIES II (LT) Up to YA265404
DISCOVERY (U) WA753113 to XA795263

SITUATION:
NOISE FROM ENGINE VALVE TRAIN/ROCKER ARMS

Customer complaints of a rattling/tapping noise from the engine found to originate from rocker shaft area may be the result of the hardened push-rod cup being insecure in the rocker arm.

RESOLUTION:

NOTE:
This bulletin supersedes and replaces TIB 12/01/981NAS.

INSPECT AND REPLACE ROCKER ARMS

Investigate customer complaints of valve rattling/tapping noise on vehicles within the above VIN ranges and identify rocker arms with loose push-rod cups. If noisy or loose rocker arms are encountered during the inspection, replace all rocker arms with updated parts.





PARTS INFORMATION





WARRANTY CLAIMS
Normal warranty policy and procedures apply.

REPAIR PROCEDURE:

DETERMINE FAULTY ROCKER ARMS AND REPLACE

1. Refer to Workshop Manual, Section 12, Engine Repairs, and remove both rocker covers.

2. Determine that rocker arms with loose cups are the source of the noise.

3. Locate the rocker arm casting date code on each rocker arm.

CAUTION:
Only rocker arms with date codes '00' may be used to repair valve trains. Use of early production rocker arms may result in a reoccurrence of the problem.





4. Refer to Overhaul Manual LRL0004ENG and replace all rocker arms manufactured prior to a '00' date code with new rocker arms having date code '00' or above. (Figure 1)

5. Assemble and install rocker arm assemblies.

6. Install rocker arm covers.

7. Start the engine and confirm that the rattling/tapping noise has been resolved.