EXHAUST LEAK/NOISE REPLACE NUT/SPRING ASSY.

SUBJECT: EXHAUST LEAK NOISE OR SQUEAK AT EXHAUST PIPE TO MANIFOLD SEAL (REPLACE NUT/SPRING ASSEMBLY, STUDS, AND SEAL)

VEHICLES AFFECTED: 1992 N CARS WITH 2.3L ENGINES PONTIAC GRAND AM OLDSMOBILE ACHIEVA BUICK SKYLARK

THIS BULLETIN** IS BEING REVISED TO UPDATE THE EXHAUST SEAL PART NUMBER, AND ADD INFORMATION TO THE "CORRECTION" AND "WARRANTY INFORMATION" SECTIONS.

CONDITION:

--------- Exhaust leak noise at exhaust manifold to exhaust manifold pipe seal during heavy load (i.e., wide open throttle) while in "drive."

- OR -

Exhaust squeak at the exhaust manifold to exhaust manifold pipe seal when shifting into "drive" or "reverse" (when the engine moves on its mounts).

CAUSE:

----- Low clamp load on exhaust seal causes leaks.

High clamp load on exhaust seal causes squeaks.

CORRECTION:

---------- For vehicles built BEFORE the breakpoints below: Replace the exhaust seal, studs, nut/spring assembly if the exhaust seal leaks during wide open throttle (in "drive") or squeaks.

For vehicles built AFTER the breakpoints below: Replace the exhaust seal if the exhaust seal leaks or squeaks.

SERVICE INFORMATION:

Refer to Section 6F in appropriate service manual for replacement procedure of the exhaust seal, studs, nut/spring assembly.

Following are the vehicle VIN breakpoints for the cars which may exhibit the exhaust leak or squeak. For vehicles built before the VIN breakpoint (replace seal, studs, nut/spring assembly)

YEAR CAR PLANT FROM TO ---- --- ----- ---- -- 1992 Pontiac - N Lansing North Start of Production NMO31509

1992 Pontiac - N Lansing South Start of Production NC216965

1992 Oldsmobile-N Lansing North Start of Production NM401575

1992 Buick - N Lansing South Start of Production NC620454

PARTS INFORMATION:

Part Numbers Part Description per Car ------------ ---------------- ----------------- 24570569 Nut/Spring Assembly 2

24573215 Stud 2

22545205 Seal 1

For vehicles repaired under warranty use:

For vehicles built before the VIN breakpoint (replace seal, studs, nut/spring assembly)

Labour Time: 0.4 hour

For vehicles built after the VIN breakpoint (replace seal only)

Labour Operation: L2090

Labour Time: 0.3 hour

Bulletin Reference-

GM of Canada 92-623-102 Pontiac Division 92-6-20 Oldsmobile Division 92-T-54 Buick Division 92-6-4

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.