Exhaust - Noise From Exhaust Seal & Front Exhaust Pipe
File In Section: 6 - EngineBulletin No.: 57-66-01
Date: May, 1995
Subject:
Exhaust Noise Between Exhaust Seal and Front Exhaust Pipe (Replace Exhaust Seal and Front Exhaust Pipe)
Models:
1992-93 Buick Skylark
1992-93 Oldsmobile Achieva
1992-93 Pontiac Grand Am
with 3300 Engine (VIN N - RPO LG7)
CONDITION
Some owners may comment about an engine exhaust noise that is traceable to the vicinity of the exhaust seal and front exhaust pipe connection.
CAUSE
The front exhaust pipe flange surface that mates to the exhaust seal may be worn through and split, causing an exhaust noise.
CORRECTION
Replace the current exhaust seal and front exhaust pipe with a service seal and pipe. The service seal is made from different material which is not as abrasive as the production seal. The service front exhaust pipe is a replacement unit without an oxidation catalytic converter attached to it.
SERVICE INFORMATION
To diagnose the condition, the technician should start the vehicle and listen for exhaust noise near the exhaust seal.
If a noise is detected in this area, follow the procedure outlined below to install the service front exhaust pipe:
1. Remove the front exhaust pipe from the vehicle.
Figure 2:
2. Separate the oxidation catalytic converter from the production front exhaust pipe by cutting the pipe with appropriate tubing cutters as close to the weld as possible. Refer to illustration.
3. Remove all burrs from the ID of the catalytic converter inlet pipe.
4. Install a new service exhaust seal onto the right exhaust manifold.
5. Attach the service front exhaust pipe to the exhaust manifold.
6. Slip the clamp over the oxidation catalytic converter inlet pipe.
7. Slip the oxidation catalytic converter onto the front exhaust pipe.
8. Install a new oxidation catalytic converter to intermediate pipe gasket, if needed, and fasten the intermediate pipe to the rear of the oxidation catalytic converter.
9. Tighten the exhaust clamp.
10. Start the vehicle and insure no exhaust leaks are present.
PARTS INFORMATION
Parts Information:
Parts are currently available from GMPSO.
Warranty Information:
WARRANTY INFORMATION