Cylinder Head - Revised Bolt Torque Update

9224buick02

Bulletin
90-6A-1A

Date
Nov., '89

Ref. No.
90-009A-6A

Corp. Ref. No.
906108R


SUBJECT:
SERVICE MANUAL UPDATE - SECT. 6A - REVISED CYLINDER HEAD BOLT TORQUING PROCEDURE


MODELS AFFECTED:
1989-90 ELECTRA WITH 3800 (VIN CODE C) 1989-90 LESABRE WITH 3800 (VIN CODE C) 1989-90 RIVIERA/REATTA WITH 3800 (VIN CODE C)


IMPORTANT:
This bulletin revises the cylinder head bolt torquing procedure for 3800 (VIN C) that appears in the 1989 and 1990 Service Manuals. The procedure for the 3800 (VIN C) is the same as that for the 3300 (VIN N). The bolt torquing sequence remains the same for both engines.


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, GM 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~ in sequence using J36660 Torque, Angle Meter.

8. Rotate the center four bolts an additional 30~ 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