Colorado 4WD L5-3.7L (2007)
Exhaust Manifold: Customer Interest
Exhaust System - Rattles/Buzzes At Idle/Start Up
TECHNICAL
Bulletin No.: 08-06-05-006F
Date: January 28, 2011
Subject: Exhaust System Rattle, Buzz, Noise (Realign Exhaust System / Nut Replacement)
Models:
2007-2011 Chevrolet Colorado
2007-2011 GMC Canyon
Equipped with 2.9L or 3.7L Engine Only (VINs 9, E - RPOs LLV, LLR)
Supercede:
This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 08-06-05-006E (Section 06 - Engine/Propulsion
System).
Condition
Some customers may comment on a rattle noise or buzz/vibration coming from under the vehicle during any of the following conditions:
-
when vehicle is first started
-
when vehicle is idling
-
upon acceleration
Cause
This condition may be caused by a misalignment of the exhaust manifold assembly to the catalytic converter or exhaust system nuts not torqued properly.
This could result in contact between the muffler (most forward hanger) and the frame and/or the catalytic converter pipe assembly to torsion bar and/or
housing.
Correction
Important
DO NOT REPLACE THE EXHAUST SYSTEM OR MUFFLER FOR THIS CONDITION. Muffler assemblies should not be replaced for a loose
nut or misalignment condition.
Inspect the exhaust system clearance at the following areas listed below.
Front Hanger to Frame Contact
1. Inspect the clearance between the frame and the muffler hanger.
Converter Pipe to Torsion Bar Housing
