FUEL LINE KNOCK OR RATTLE NOISE AFTER COLD START

FUEL LINE KNOCK/RATTLE

1988 GRAND PRIX WITH AUTOMATIC TRANSMISSION (RPO MD9/ME9)

Some 1988 Grand Prix vehicles with automatic transmissions (RPO MD9/ME9), assembled prior to VIN JF216305, may exhibit a light hammering/rattle type noise audible after a cold start at low ambient temperatures.

This condition may be caused by pressure pulsations in the fuel system generated by fuel injector operation, resulting in hydraulic hammering in chassis fuel pipes.

Vehicles exhibiting this condition may be repaired by installation, following applicable shop manual procedures, of a new fuel return hose and stand-pipe assembly, P/N 10114735, which will reposition stand-pipe in a upward vertical position.

NOTICE: THE EXISTING AND NEW FUEL RETURN HOSE ASSEMBLIES ARE FORMED PARTS. ATTEMPTING TO INVERT THE STAND-PIPE ON THE EXISTING PART BY TWISTING THE HOSE MAY ADVERSELY AFFECT ENGINE OPERATION AND/OR HOSE INTEGRITY.

Use applicable Labor Operation Number and Time.

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.