Exhaust System - Moan/Boom
File In Section: 6 - EngineBulletin No.: 43-66-03
Date: October, 1994
Subject:
Exhaust Moan/Boom (Install Dampener)
Models:
1994-95 Buick Roadmaster
1994-95 Chevrolet Caprice Classic, Impala Super Sport with 5.7L V8 Engine (VIN P - RPO LT1)
Condition
Some customers may comment on an exhaust moan/boom evident when the engine is operated at approximately 1,200 rpm. This condition is most apparent at lower ambient temperatures after a cold start.
Cause
Vehicle exhaust system excitation caused by engine exhaust pulse induced vibration.
Correction
Install dampener to LH catalytic converter flange using components and service procedure as indicated:
Service Procedure
1. Raise and suitably support vehicle.
2. Locate and enlarge the two holes of the LH catalytic converter attaching flange shown in Figure 1 utilizing a 25/64" drill bit.
3. Using an air hammer and chisel bit or die grinder, remove remaining raised boss from around holes that were enlarged in step two (2).
4. Install dampener, P/N 10272298, as shown in Figure 2 and secure in position using two (2) bolts, P/N 3522364, two (2) washers, P/N 3790768 and two (2) nuts, P/N 10255857.
5. Holding bolts with a back-up wrench, torque nuts to 50 N-m (37 lb.ft.).
6. Lower vehicle.
Parts Information Parts will be available from GMSPO on October 10, 1994.
Warranty Information For vehicles repaired under warranty, use:
Labor Operation Labor Time
L2008 .3 Hr.