REVISED CYLINDER HEAD BOLT TORQUING PROCEDURE

Models Affected: 1989-90 BONNEVILLE 3800 (VIN C) ENGINE

IMPORTANT: This bulletin revises the cylinder head bolt torquing procedure for 3800 (VIN C) that appears in the 1989 and 1990 Service Manuals.

INSTALL OR CONNECT

1. Clean threads in the block using a 7/16-14 tap. 2. Clean bolt threads using a wire brush. 3. Cylinder head gasket on block. 4. Apply sealant, part number 1052080 on bolt threads. 5. Cylinder head bolts. 6. Tighten cylinder head bolts to 47 N.m (35 lbs.ft.) in sequence. 7. Rotate each bolt 130 degrees in sequence using J36660 torque angle meter. 8. Rotate the center four bolts an additional 30 degrees in sequence using J36660 torque angle meter. 9. Pushrods, guide plate and rocker arm assemblies.

Apply Threadlock, GM part number 12345493, to rocker arm pedestal bolts before assembly.

Tighten rocker arm pedestal bolts to 38 N.m (28 lbs. ft.).

10. Intake manifold 11. Valve cover 12. Exhaust manifold

Front (left) cylinder head.

- A/C compressor bracket bolt to 70 N.m (52 lbs. ft.). - Generator support bracket to cylinder head. - Generator. - C3I and spark plug wires.

Rear (right) cylinder head.

- Belt tensioner assembly. - Power steering pump. - Fuel line heat shield.

13. Negative battery cable.

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.