NEW EXHAUST MANIFOLD NOISE CONDITION NEW PART

VEHICLES AFFECTED: 1985-89 P2, P3, P4 TRUCKS WITH 4.8L (VIN T) ENGINE

THIS BULLETIN CANCELS AND REPLACES BULLETIN (#936602) #89-648-100 DATED (11/27/89).

Some 1985-89 P-Trucks with 4.8L engines may experience a condition where an exhaust leak develops between the manifold and cylinder head mating surface causing a noise condition.

Starting in late 1989 production, a new nodular iron exhaust manifold was released for the 4.8L engine. Along with this improved manifold, new and improved gaskets were also released. Theses new parts can be used on earlier year trucks. The new parts are as follows:

Part Number Usage Quantity

**10141248 Gasket - Inlet to exhaust manifold 1 **10141249 Gasket - Inlet and exhaust manifold 1 * 10141251 Manifold - Exhaust

IMPORTANT: THIS NEW MANIFOLD DOES NOT INCORPORATE AN E.F.E. (EARLY FUEL EVAPORATION) VALVE. CAP VACUUM FITTING AND REMOVE E.F.E. LINES PER ATTACHED ILLUSTRATION.

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.