Engine - Knocking/Chattering Noises: Overview

Bulletin No.: 003/96
Issued: 04/25/96
Revised: 11/21/96

Category
B

Applicable Model/s
MPV and 929

Subject:
VARIOUS CASES OF ENGINE NOISE

NOTE:
This bulletin replaces the following bulletins: Cat B, 001/93, 006/93, 001/94, 012/95, 03/96.

APPLICABLE MODELS/VINS
Refer to each symptom for applicable models and VIN ranges.

DESCRIPTION
This Service Bulletin contains detailed repair procedure, countermeasure parts and warranty information for current engine noise symptoms.





The symptoms listed below, include a brief description of the noise, its location and timing. The "Diagnostic Flow Chart" illustrates the procedure for diagnosing engine noise.

This bulletin addresses only the symptoms listed below. For information on other symptoms, refer to the appropriate troubleshooting procedures in the applicable workshop manual.

SYMPTOMS

A. Carbon Accumulation (1992-95 929 & 1989-95 MPV) - Top of the engine knocking noise, occurs in time with crankshaft rotation during cold engine start-up.

B. Hydraulic Lash Adjuster (HLA) Noise (1989-94 MPV with a V6) - Top of engine chatter, several times faster than crankshaft rotation.

C. Crankshaft Noise (1992 929) - Bottom of engine knocking noise, occurs in time with crankshaft rotation at normal operating temperature.

D. Piston Slapping Noise (1992-93 929 & 1989-93 MPV with a V6) Top of engine noise, occurs in time with crankshaft rotation under load on acceleration.





Disclaimer