COOLING FAN VIBRATION IDLE NOISE RELATED

SOME BASE HEATER (RPO C41) EQUIPPED 1982 CAVALIERS MAY EXHIBIT A VIBRATION AND/OR NOISE AT IDLE WHEN THE COOLING FAN IS OPERATING. IF THIS CONDITION IS ELIMINATED BY DISCONNECTING THE LEAD TO THE TEMPERATURE SWITCH LOCATED ON TOP OF THE THERMOSTAT HOUSING, THE CONDITION IS ATTRIBUTABLE TO THE RESONANT FREQUENCY OF THE ELECTRIC COOLING SYSTEM. ELIMINATION OF THIS VIBRATION AND/OR NOISE WILL REQUIRE SECURING THE FAN GUARD TO LEFT FAN MOUNTING LEG FOLLOWING SERVICE PROCEDURE BELOW: 1.DISCONNECT NEGATIVE BATTERY LEAD AT THE BATTERY. 2.DRILL A .125 INCH DIAMETER HOLE 1/4 INCH FROM THE REAR EDGE OF THE FAN GUARD, CENTERING ON THE LEFT MOUNTING LEG, THROUGH THE GUARD AND TOP SIDE OF THE TUBULAR LEG (FIGURE 1). 3.SECURE THE FAN GUARD TO THE MOUNTING LEG UTILIZING A #8 X 1/2 HEXAGON WASHER HEAD TAPPING SCREW, P/N 9422046. 4.RECONNECT NEGATIVE BATTERY LEAD.

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.