GM Service Manual Online
For 1990-2009 cars only

WHISTLING OR WHINE NOISE UP TO 2500 RPM

WHISTLING OR WHINING NOISE FROM ENGINE ASSEMBLY

1986 CUTLASS CIERA AND DELTA 88 MODELS 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, remove the serpentine belt and start the engine, this will eliminate the possibility of the alternator as the noise source. If the noise is still present with the serpentine belt removed, the camshaft should then be replaced, this 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.