For 1990-2009 cars

# ROUGH IDLE RETORQUE CARB TO PLENUM BOLTS

A LEAN OR ROUGH IDLE CONDITION EXHIBITED ON "F" SERIES WITH THE 4.9L TURBO ENGINE MAY BE CAUSED BY IMPROPERLY TORQUED CARBURETOR TO PLENUM ATTACHING BOLTS, OR LEAKING GASKET BETWEEN TURBO COMPRESSOR AND THE INTAKE MANIFOLD. THE RECOMMENDED TORQUE FOR THE CARBURETOR TO PLENUM ATTACHING BOLTS IS 17 N.M (13 LB. FT.). TORQUE FOR THE COMPRESSOR HOUSING TO THE INTAKE MANIFOLD BOLTS IS 37 N.M (27 LB. FT.). LOW TORQUE ON THESE BOLTS MAY CAUSE THE CONDITION DESCRIBED ABOVE. IF, AFTER PROPERLY TORQUING BOLTS, THE CONDITION REMAINS, REFER TO THE 1981 SERVICE MANUAL FOR FURTHER DIAGNOSIS.

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.