Oil Pan/Filter Housing - Buzzing, Rattling Noise

GROUP 11
Engine

Bulletin Number
11 05 00

Woodcliff Lake, NJ
June 2000
Service Engineering

SUBJECT:
Buzzing / Rattling Noise from Engine Compartment

MODELS:
Z3 with M52TU engine from 9/98 up to 1/2000 production
E46 with M52TU engine from 9/98 up to 1/2000 production
E39 with M52TU engine from 9/98 up to 1/2000 production

Situation:
A buzzing or rattling noise may be heard coming from the front oil pan and oil filter housing support areas of the engine on some M52TU powered vehicles.

The noise is most noticeable when all of the following conditions exist:

* During the engine warm up phase

* Engine speed at 1200 to 2000 rpm steady speed or during acceleration / deceleration through the 1200 to 2000 rpm engine speed range

* Vehicle stationary (hood open or closed) or while driving (hood closed)

Note:
This noise should not be confused with the VANOS switching sound (normal operating noise) which is heard with the hood open when briefly rewing the engine from idle speed.

Cause:
The noise is caused by a resonance / pulsation in the oil circuit (engine lubrication system) due to oil pump pulsations.

Correction:
Production fix:

A new design oil pump is being used in production since 1/2000 on M52TU engines which will be carried over to M54 engines.

The new pump design eliminates the noise due to oil pump pulsations.

Note:
The completely new design of this pump (short oil pump with a sheet metal oil deflector) does not allow it to be retrofitted to M52TU engines produced prior to 1/2000.

Field fix:

On a customer complaint basis only on vehicles produced before 1/2000, replace the oil pump with a modified oil pump BMW part number 11 41 7 507 350.

The modified oil pump assembly incorporates a restrictor in the pilot control orifice which dampens the pulsations in the oil circuit thus eliminating the buzzing or rattling noise.

See the appropriate repair manual group 11, section 11 41 000 for oil pump removal and installation instructions.





PARTS INFORMATION

Note:
In addition to the oil pump listed above other "small parts/hardware" will be needed for this repair. Refer to the appropriate model in EPC for other miscellaneous part numbers, i.e., 0-rings, seals, self-locking nuts, etc.





WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.