S15/T15 Jimmy 2WD V6-4.3L VIN W (1998)
Timing Chain Tensioner: All Technical Service Bulletins
Engine - Engine Rattle at 1,800-2,200 RPM's
Bulletin No.: 03-06-01-024C
Date: August 30, 2006
TECHNICAL
Subject:
Rattle Noise In Engine (Install Timing Tensioner Kit)
Models:
1996-2003 Chevrolet Astro, Blazer, Express, S-10, Silverado and P Models
1996-2003 GMC Jimmy, Safari, Savana, Sierra, Sonoma
1996-2001 Oldsmobile Bravada
with 4.3L V6 Engine (VINs W, X - RPOs L35, LF6, LU3)
Supercede:
This bulletin is being revised to add additional models. Please discard Corporate Bulletin Number 03-06-01-024B (Section 06 - Engine/Propulsion
System).
Condition
Some customers may comment on a rattle-type noise coming from the engine at approximately 1800 to 2200 RPMs.
Cause
The spark, rattle-type noise may be caused by torsional vibration of the balance shaft.
Correction
If detonation noise is present, perform detonation/spark knock diagnostics first.
Install a new tensioner assembly kit using the procedure below.
Remove the engine front cover. Refer to SI for engine front cover removal procedure.
Remove the crankshaft sensor reluctor ring and line up the timing marks on the crank gear and cam shaft gear.
Remove the camshaft gear and chain. For model years 1996-1998, remove the crankshaft sprocket using J 5825-A.
Pull the shipping pin and discard. Remove the nylon timing chain tensioner blade from the timing chain tensioner bracket.
Position the bracket on the front of the engine. The upper two attaching holes of the bracket will line up with the center two engine front cover bolt holes.
The lower bracket holes will line up with the engine front cover alignment holes.
