SERVICE MANUAL UPDATE SEC. 6A EXHAUST MANIFOLD REPLACEMENT

SUBJECT: SERVICE MANUAL UPDATE - SECTION 6A RIGHT REAR EXHAUST MANIFOLD REPLACEMENT (REVISED PROCEDURE)

VEHICLES AFFECTED: 1990-91 BUICK AND OLDSMOBILE A-CAR W/3.3

The following Right Rear Exhaust Manifold Replacement Procedure updates and replaces the current procedure found in the the 1990-91 Oldsmobile and Buick A-car Service Manual.

Exhaust Manifold (Right Rear) Refer to Figures 1 and 2

Remove or Disconnect

1. Negative battery cable. 2. Air cleaner and duct assembly. 3. Serpentine belt. 4. Drain coolant. 5. Power steering pump brace, and bolts from mounting bracket, set pump forward. 6. Spark plugs wire loom, wire harness, set aside. 7. Oxygen sensor wire connector. 8. Engine lift bracket nuts from exhaust manifold. 9. Coolant tube, engine lift bracket and fuel line clamp screw from coolant tube assembly, move aside. 10. Right bank of spark plugs. 11. Exhaust crossover tube. 12. Transaxle fill tube retaining bolt, move tube for access. 13. Raise vehicle and suitably support. Refer to General Information (Section 0A). 14. Exhaust pipe from manifold. 15. Lower vehicle. 16. Exhaust heat shield retaining nuts, pull shield back. 17. Manifold studs and manifold. 18. Exhaust heat shield.

Install or Connect

1. Manifold, studs and heat shield.

Tighten Studs to 52 N.m (38 ft,lbs.

2. Exhaust heat shield retaining nuts.

Tighten Nuts to 26 N.m (18 ft.lbs.)

3. Raise vehicle and suitably support. Refer to General Information (Section 0A). 4. Exhaust pipe to manifold.

Tighten Bolts to 30 N.m (22 ft.lbs.)

5. Lower vehicle. 6. Transaxle fill tube retaining bolt.

Tighten Bolt to 25 N.m (18 ft.lbs.)

7. Exhaust cross over pipe. 8. Right bank of spark plugs.

Tighten Plugs to 27 N.m (20 ft.lbs.)

9. Coolant tube, engine lift bracket and fuel line clamp screw to coolant tube assembly. 10. Engine lift bracket nuts to exhaust manifold.

Tighten Nuts to 30 N.m (22 ft.lbs.)

11. Oxygen sensor wire connector. 12. Spark plug wire loom and wire harness. 13. Power steering pump brace, pump bolts to mounting bracket.

Tighten Tensioner brace bolt to 26 N.m (19 ft.lbs.) Pump mounting bolts to 27 N.m (20 ft.lbs.)

14. Refill coolant. 15. Serpentine belt. 16. Air cleaner and duct assembly. 17. 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.