This bulletin cancels and supersedes Dealer Technical Bulletin 93-T-41 which should be discarded.
CONDITION: Some customers may comment about a grunt, squawk or squeak noise when shifting from park to reverse or drive. The same noise may also be heard during heavy engine load, such as quick acceleration. The noise will most likely occur in cold ambient temperatures or wet conditions. This noise may be misdiagnosed as coming from the exhaust seal. Use the following procedure to determine the location of the noise.
CAUSE: On 1992-93 vehicles, the lower engine mount strut rubber may move against its metal casting during the shift or heavy engine loads. On 1992 Quad 4 engines, a similar noise can be caused by high clamp load on the exhaust seal. This condition is addressed by Dealer Technical Bulletin 92-T-54A.
CORRECTION: Use the diagnosis below. When the diagnosis indicates the exhaust system is at fault on 1992 Quad 4 engines, refer to Dealer Technical Bulletin 92-T-54A to repair the exhaust system. All 1993 model year production vehicles with Quad 4 engines have a redesigned exhaust manifold and seal. Install revised lower engine mount strut, P/N 22595752, when diagnosis indicates the lower engine mount strut is at fault. VINs starting with PM035485 have the revised lower engine mount strut installed in production.
Spray 3M silicone lubricant P/N 51135-08935 or equivalent on the lower engine mount strut between the rubber and metal.
If the noise still exists, refer to Dealer Technical Bulletin 92-T-54A for exhaust system seals. If the noise is gone, do not replace the lower engine mount strut. Engineering is working on an updated part to repair this condition. The silicone lubricant will eliminate the condition for a short time only.
Labor Operation Number: T1948 - Lower engine mount strut diagnosis T3368 - Lower engine mount strut diagnosis and replace. Labor Time: 0.2 hour for T1948 0.4 hours for T3368 Trouble Code: 92
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.