Sunfire L4-2.2L VIN 4 (1996)
Exhaust Resonator: Customer Interest
Exhaust - Metallic Noise or Rap Heard on Cold Exhaust
File In Section: 6 - Engine
Bulletin No.: 63-66-04C
Date: September, 1998
Subject:
Metallic Noise or "Cold Rap" Heard on Cold Exhaust Systems During Free Rev or Engine Load (Install Resonator Assembly)
Models:
1995-98 Chevrolet Cavalier
1995-98 Pontiac Sunfire
with 2.2L Engine (VIN 4 - RPO LN2)
This bulletin is being revised to change labor time information. Please discard Corporate Bulletin Number 63-66-04B (Section 6 - Engine).
Condition
Some owners may comment that a metallic noise or "cold rap" may be heard on cold exhaust systems. Condition occurs prior to muffler inlet gasses
exceeding 400°F (204°C) and is found at 2800 rpms during free rev or engine load.
Cause
The resonator frequencies, in combination with ambient conditions and exhaust tuning, may create the "cold rap" condition.
Correction
