Engine - Accessory Drive Noise: Overview
File In Section: 6 - EngineBulletin No.: 77-61-19
Date: November, 1997
Subject:
Accessory Drive Noise (Follow Diagnostic Procedures)
Models:
1997 Cadillac DeVille, Eldorado, Seville 1997 Oldsmobile Aurora
with 4.0L, 4.6L Engines (VINs C, Y, 9 - RPOs L47, LD8, L37)
Condition
Some vehicles may exhibit chirping, ticking, knocking, or "trashy" noises from the front of the engine. The service writer and technician should note in writing on the Repair Order the conditions associated with the noise such as outside ambient and engine operating temperatures, and when the noise is observed. The service writer should personally observe and describe the type and location of noise on the Repair Order. The noise may sound like an under hood squeak, a metallic trashy noise, or an inside vehicle thump, etc. The service writer should ask the owner it the noise occurs following start up after an overnight soak, and whether the noise reduces or goes away completely as the engine warms up. Write the customer response on the Service Repair Order.
Cause
This condition is caused by pulley misalignment of the accessory drive system.