GM Service Manual Online
For 1990-2009 cars only

'BOOM' NOISE IN PASSENGER COMPARTMENT ONLIGHT ACC.

Subject: "BOOM" NOISE IN PASSENGER COMPARTMENT ON LIGHT ACCELERATION (REPLACE MUFFLER)

Models Affected: 1992-93 BONNEVILLE MODELS WITH 3.8L (L27) ENGINE

CONDITION:

--------- Exhaust "lock-up boom" on light acceleration in fourth gear. The torque converter clutch in the transmission locks and a loud booming noise is heard in the passenger compartment. It will get progressively louder until clutch disengages.

CORRECTION:

---------- A new muffler has been released to correct the above condition.

1992 model year vehicles use P/N 25609138 1993 model year vehicles use P/N 25620651

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Labor Operation Number: L2584

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.