SERVICE MANUAL UPDATE-SEC. 6A2 CYLINDER HEAD REPLACEMENT

SUBJECT: SECTION 6A2 - CYLINDER HEAD REPLACEMENT

VEHICLES AFFECTED: 1990-93 "R" MODELS WITH 1.6/1.8L DOHC ENGINES (VIN 5, 8 / RPO LWO, LV6)

APPLICATION:

----------- 1990-91 Geo Storm models equipped with 1.6L DOHC engine VIN 5 (RPO LWO)

1992-93 Geo Storm/Asuna Sunfire models equipped with 1.8L DOHC engine VIN 8 (RPO LV6)

This bulletin is an addition to the procedures located under "Cylinder Head" found in Section 6A2 of the 1990-91 Geo Storm Service Manual (ST371-90 and ST271-91, respectively) and "Cylinder Head and Valve Off-Vehicle Service" found in Section 6A2 of the 1992-93 Geo Storm Service Manuals (ST371-92 and ST371-93, respectively).

When replacing the cylinder head, the oil flow check valve and the cylinder head oil control valve must be transferred to the new cylinder head (Figure 1). These two valves are located beneath the intake camshaft between the number 3 and number 4 cylinder bores. Both valves are threaded into the cylinder head.

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.