WHINE / WHISTLE UP TO 2500 RPM CHECK INTAKE MANIFOLD SEALING

VEHICLES AFFECTED: 1986 'A' and 'H' Cars Equipped With 3.8L V-6 (VIN Code 3) Engines

If a whistling or whining noise, that sounds somewhat like an intake air leak, occurs on one of the above vehicles up to approximately 2500 rpm, the intake manifold sealing areas should be checked for leaks. This can best be accomplished using a plews type oiler, or some other similar tool, and applying a small amount of oil or water to the intake manifold sealing surfaces. If the noise is still evident, the serpentine belt should be removed and the engine run again. If the noise is still audible, the camshaft should then be inspected.

If inspection reveals minute flat spaces or ridges on the lobes of the camshaft, that look like those in the illustration, replacing the camshaft should eliminate the noise.

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.