ENGINE OVERHEATING CONDITION (DIAGNOSIS) INSTALL NEW GAUGE

Subject: PERCEIVED ENGINE OVERHEATING CONDITION (DIAGNOSIS/INSTALL NEW GAUGE)

Models Affected: 1988-91 LEMANS

The purpose of this new gauge in production on the 1991 LeMans is to address customer comments of engine overheating.

The new gauge repositions two of the graduations on the face of the gauge. The positioning of the "Midpoint" and the "Three-Quarter" graduation have been moved upward slightly. The revised position of the "Three-Quarter" graduation will allow the temperature needle to be positioned at or near that graduation rather than above it during normal engine operating temperatures.

If a customer comment is received for engine overheating, a complete cooling system inspection must be performed. This includes verifying that the engine operating temperature is normal using a "Tech 1" diagnostic computer scan tool. If no apparent reason for the over- heating can be found, then the new gauge P/N 96137541 may be installed in place of the existing gauge. The standard temperature gauge replacement procedure as found in the Le Mans Service Manual should be followed.

Part is currently available from GMSPO.

IMPORTANT: After installing the new temperature gauge, the customer should be advised that it is normal for the temperature needle position to be at or near the "Three-Quarter" graduation during normal engine operation.

Usage of the new P/N gauge became effective in production with VIN MB310798 for the 1991 LeMans.

Use applicable labor operation.

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.