Engine - Irregular Clicking Noise

GROUP 11
Engine

Bulletin Number
11 06 97

Woodcliff Lake, NJ
December 1999
Product Engineering

This Service Information bulletin supersedes S.I. 11 06 97 dated December 1998 which should be removed and discarded from your S.I. binder.

SUBJECT:
Irregular Engine Clicking Noise

MODEL:
All with M60 and M62 engines.

Situation:
Isolated reports have been received of a loud clicking noise coming from the lower crankcase area, cylinder bank 5 - 8.

The noise which has also been described as a loud irregular tapping (similar to the tapping of a mechanical type writer) is best duplicated with the engine at operating temperature, engine speeds from idle to approximately 2000 RPM and with an engine load (transmission in drive, and conditioning switched on, etc).

This noise complaint is not caused by mechanical damage to any engine components and its cause, in no way, compromises the reliability of continuous engine operation.

Correction:
Only if a customer complaint of an inconsistent engine clicking noise is received and the noise verified under the conditions described above, should the crankshaft main bearing shells be replaced.





The bearing shell color configuration should be used to eliminate the clicking noise complaint:

Note:
This bearing shell color configuration is contrary to the information published in the repair manual for conventional crankshaft main bearing replacements.

When installing crankshaft bearing shells the minimum radial crankshaft bearing play should not be less than 0.02 mm (0.001 in.) as stated in Technical Data, section 11 21.





If a crankshaft is installed with undersized main bearing journals the part numbers in this table apply for this repair:





The factory main journal grinding stage on a crankshaft is identified by the number of paint stripes on the front counter weight of the crankshaft. (see illustration)

If the paint stripes are no longer clearly visible (stripes wear oft over time) or no paint stripes are visible at all a micrometer must be used to measure and verify the crankshaft journal diameter.

The measured value should then be compared to the specifications in Technical Data section 11 21 for the correct main bearing shell application.

Procedure:
The complete repair procedure for replacing the main crankshaft bearing shells is outlined in the repair manual, section 11 21.





Warranty Information:
Covered under the terms of the BMW New Car Limited Warranty.