Engine - Rattle Noise Coming from Front (VANOS area): Overview

GROUP 11
Engine

11 04 01

Woodcliff Lake, NJ
July 2001
Service Engineering

SUBJECT
VANOS Rattle Noise After Engine Start

MODEL
E39 M5 and E52 Z8 with S62 engine produced up to 11/30/00.

SITUATION

A rattling noise coming from the front of the engine (VANOS area) may be heard for a few seconds after start up.

CAUSE

The VANOS adjusting units may cause a momentary rattling noise after the engine is started due to varying torque of the camshafts before sufficient VANOS adjustment oil pressure is built up.

When the engine is switched off, oil bleeds out of the high-pressure chamber in the VANOS adjustment cylinder. This can cause the VANOS adjustment piston to move freely against the housing during engine start up causing the momentary rattling noise.

This noise has no effect on engine power output or durability.

CORRECTION

M5 and Z8 vehicles produced from 12/1/00 incorporate a VANOS accumulator shutoff valve which prevents oil bleed off of the high-pressure chamber after the engine is switched off.

On a customer complaint basis only, a VANOS accumulator shutoff valve can be installed to eliminate the momentary rattling noise after the engine is started on vehicles produced before 12/1/00.

Note:
Three VANOS accumulator shutoff valve kits have been developed to accommodate the running production changes on M5 and Z8 vehicles.

-- Kit part number 11 36 7 832 855 should be used on M5 vehicles produced up to 8/31/00 and 11 36 7 832 856 should be used on Z8 vehicles produced up to 9/1/00. These kits include electrical and mechanical components for the VANOS accumulator shutoff valve installation.

Kit part number 11 36 7 832 858 should be used on M5 and Z8 vehicles produced from 9/1/00 up to 11/30/00. This kit includes mechanical components for the VANOS accumulator shutoff valve installation since the wiring harness is already installed during production on these vehicles.

Section A of the procedure below outlines the wiring installation instructions needed to install the VANOS accumulator shutoff valve on M5 and Z8 vehicles produced up to 8/31/00.

Section B of the procedure outlines the installation of a VANOS accumulator shutoff valve (mechanical components only since the wiring harness is already installed during production on these vehicles) on M5 and Z8 vehicles produced from 9/1/00 up to 11/30/00.

Note:
Both section A and B procedures must be used on M5 and Z8 vehicles produced up to 8/31/00 to complete the VANOS accumulator shutoff valve installation.





PARTS INFORMATION





WARRANTY INFORMATION

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





DISCLAIMER