OIL PRESSURE LIGHT MAY FLICKER AT IDLE IN HOT AMBIENT TEMP.

VEHICLES AFFECTED: 1988-89 A/J/L/W CARS-W/2.8/3.1

Chevrolet: 1988 J and L, 2.8L 1989 J and L, 2.8L Pontiac: 1989 A and W, 2.8L and 3.1L Oldsmobile: 1989 A 2.8L, W 2.8L and 3.1L Buick: 1989 W, 2.8L and 3.1L Cadillac: 1988 J, 2.8L

Condition:

--------- The oil pressure light may flicker at idle, in very hot ambient temperatures. This condition may occur on 1988 J and L cars, and on 1989 A,J,L, and W cars, with 2.8L or 3.1L engines, with optional gauge packages (these vehicles use both a gage and an oil pressure warning light).

Cause:

----- The diaphragm, which moves with changes in oil pressure, may by affected by high ambient temperatures in the sensor, because the sensor is not vented. The high temperature causes the air inside the sensor to expand, pushing against the diaphragm, giving a lower than actual reading, which may cause the warning light to flicker at idle.

Correction:

----------- A new vented oil pressure sensor, part number 10096199, has been released for 1990 Production. This new sensor should be used for the above applications for service.

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.