GM Service Manual Online
For 1990-2009 cars only

ENGINE MOAN 1982 REVISED INFORMATION

A RESONANCE SOUND OR MOAN: 1) AT 1800-2000 ENGINE RPM (45-50 MPH THIRD GEAR), AND/OR; 2) AT OFF IDLE 1200-1400 ENGINE RPM (10-15 MPH FIRST GEAR) MAY BE IMPROVED AS FOLLOWS: 1.1800-2000 ENGINE RPM (45-50 MPH THIRD GEAR) ENGINEERING HAS DEVELOPED AN INTERMEDIATE PIPE HANGER FRONT BRACKET ASSEMBLY KIT WHICH WILL HELP ISOLATE THE EXHAUST SYSTEM FROM THE BODY. THIS KIT MAY BE OBTAINED FROM WDDGM, PART NUMBER 25515654. 2.1200-1400 ENGINE RPM (10-15 MPH FIRST GEAR) A.REMOVE CONDENSER INLET TUBE CLIP AND DISCARD. INSTALL STRAP SUCH AS PART NUMBER 14009215, OR EQUIVALENT, AROUND A/C LINE AND THE FUEL VAPOR HOSE AS SHOWN IN ILLUSTRATION. (STRAP SHOULD NOT COLLAPSE FUEL VAPOR HOSE). INSTALL A SECOND STRAP AS SHOWN IN THE ILLUSTRATION, TO MAKE SURE THAT THE LINE IS NOT IN CONTACT WITH THE FRAME RAIL OR A.I.R. PUMP PULLEY. B.CHECK AIR CONDITIONING BELT TO ENSURE IT IS TIGHT. IT NOT, TIGHTEN TO ITS HIGH LIMIT. BE SURE ALL AIR CONDITIONING COMPRESSOR MOUNTING BOLTS ARE TORQUED TO SPECIFICATIONS. (LIST BELT SPECIFICATION AND BOLT TORQUE).

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.