For 1990-2009 cars

# WHINE OR WHISTLE NOISE FROM REAR OF VEHICLE

CHANGE TO EVAPORATIVE EMISSION CONTROL SYSTEM (EECS) WHINING/WHISTLE NOISE FROM REAR OF VEHICLE

#### MODELS AFFECTED 1988 FIREBIRD WITH 5.OL OR 5.7L ---------------

Some 1988 Firebird models with V-8 engines (RPO -LO3, LB9 or L98) may exhibit a "whining/whistling" type noise coming from the rear of the vehicle. This condition is most apparent when the engine is shut down after extended city stop and go driving, or operation at high ambient temperatures.

To eliminate the possibility of this occurring, an interim production change to the evaporative emission control system (EECS) was implemented on January 29, 1988, VIN breakpoint JL228575.

This change terminated usage of an in-tank pressure control valve which was part of the fuel tank sender assembly, and initiated usage of an underhood externally mounted tank pressure control valve.

Service fuel tank sender assemblies available from GMSPO are of the second design configuration without the in-tank pressure control valve feature. When replacement of a fuel tank sender assembly is required on vehicles assembled prior to the above indicated breakpoints, it will be necessary to install a fuel tank pressure/ control valve kit, P/N 10113082, in the existing hose ,assembly connecting the vapor carbon canister to the evaporative emission chassis pipe. The instructions for this installation are included in the applicable fuel tank sender assembly service kits indicated below by engine RPO.

Engine RPO P/N Description ---------- --- ----------- L03 25094673 Fuel Tank Sender Asm. Kit

LB9/L98 25094990 Fuel Tank Sender Asm. Kit.

Parts are expected to be available on July 15, 1988. Until then normal parts orders will not be accepted by GMSPO in the case of an emergency a VIP order should be processed.

#### WARRANTY INFORMATION:

Labor Operation: T1337

Labor Time : 2.3 Hours

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.