Exhaust - Moan or Hoot in the Passenger Compartment
Group Ref.: 6 - EngineBulletin No.: 436601
Date: June, 1994
SUBJECT:
EXHAUST MOAN/HOOT
(INSTALL DAMPER)
MODELS:
1994 BUICK REGAL
1995 CHEVROLET LUMINA AND MONTE CARLO
1993-94 OLDSMOBILE CUTLASS SUPREME
1994 PONTIAC GRAND PRIX
WITH 3.1L V6 ENGINE (VIN M - RPO L82)
CONDITION:
Some customers may comment on an exhaust hoot/moan audible in the vehicle passenger compartment on vehicles with single or dual exhaust. This condition is apparent when the engine is operated in the 1000-1100 or 1800-2000 RPM ranges after a cold start.
CAUSE:
Vehicle exhaust system excited by engine exhaust pulse induced vibration.
CORRECTION:
Install damper, P/N 10137383, using exhaust pipe clamp, P/N 10114791, following the procedure indicated below.
SERVICE PROCEDURE:
1. Raise vehicle.
2. Position exhaust pipe clamp, P/N 10114791, 17.5" rearward of the resonator hanger rod with stud portion of clamp pointing vertically upward (Figure 1).
3. Torque clamp nuts to 51 N-m (38 lb.ft.) and insure at least 1" of clearance is between the clamp and fuel tank.
NOTE:
Visible deformation of the pipe will occur, ensuring that clamp will not rotate.
4. Install damper, P/N 10137383, onto the outboard stud of the exhaust clamp (stud farthest from fuel tank). Secure the damper to clamp using an open-end wrench.
5. Inspect and insure at least 1" clearance is maintained between the damper and fuel tank and between the damper and the path of the rear suspension lateral link (Figure 1).
6. Lower vehicle.
PART AVAILABILITY:
Parts are currently available from GMSPO.
WARRANTY INFORMATION:
For vehicles repaired under warranty, use:
Labor Operation Labor Time
L2008 0.3 Hr.