THROTTLE BODY TO MANIFOLD GASKET REPLACE/IDENTIFICATION

VEHICLES AFFECTED: 1988 DE VILLE, FLEETWOOD, ELDORADO AND SEVILLE

With the introduction of the 4.5L V-8 engine for the 1988 model year, revisions in the throttle body bore diameter have dictated changes in the throttle body to intake manifold gasket. The diameter has changed from 35mm for the 4.lL V-8 gasket to 43mm on the 4.5L V-8 (see Figure 1).

CARE SHOULD BE TAKEN IN SERVICE OF THE GASKETS AS THEY ARE VERY SIMILAR AND COULD MISTAKENLY BE INTERCHANGED. Interchanging of the gaskets may result in poor emissions and low fuel economy. The 4.5L throttle body to manifold gasket has an identification tab to help distinguish between the 4.5L and 4.1L gaskets (see Figure 1). In the car this tab is visible when looked at from over the top of the I.S.C. motor.

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.