GM Service Manual Online
For 1990-2009 cars only

INDUCTION ROAR FROM ENGINE CHECK AIR CLEANER NUT TORQUE

MODELS AFFECTED: 1987 CENTURYS WITH 2.5L (VIN CODE R) ENGINE 1987 SKYLARKS AND SOMERSETS WITH 2.5L (VIN CODE U) ENGINES

Some 1987 Centurys, Skylarks, and Somersets with 2.5L L-4 engines may exhibit unsatisfactory levels of engine induction noise due to overtorqued wing nuts on the air cleaner cover. This condition causes the air cleaner cover to become distorted, leaving a small gap between the cover and the air filter element. Some incidents of air filters being crushed have been reported.

If customer comments are received on induction noise, remove the air cleaner and cover and check for damage. Repair the cover, if required. Check the air filter element for signs of distortion or crushing (See Illustration). Replace the air filter element, if damaged. Reinstall the air cleaner cover and wing nuts. Torque wing nuts to 1.6 - 2.4 N.m (14-21 in. lbs.). (NOTE: A technician will not normally exceed the upper limit of the torque specification if the wing nuts are hand-tightened.)


Object Number: 90242  Size: MF

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.