A knocking noise in the front area of the engine may be caused by a loose timing belt hitting the timing belt front cover. If this condition is encountered, remove the timing belt front cover and check the belt tension.
If the belt is found to be loose, remove the belt and visually inspect the root of the cogs for cracks. If cracks are apparent, replace the timing belt.
Timing belt tension specifications that appear on Page 6A2-10 in the 1982 Skyhawk OHC, 4-cylinder Engine Service Manual Supplement have been revised as follows:
New Belt 180 N (40 lbs.) Used Belt 120-160 N (26-35 lbs.)
These adjustments are to be made on a cold engine.
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.