Thought I would post this bulletin from GM that gives information about the coolant leak at the upper intake manifold gasket. Since so many people have had this issue, it might be helpfull. This is for information only.


#01-06-01-007C: Engine Coolant Consumption or Coolant Leak (Inspect for Material Degradation/Replace Intake Manifolds) - (Sep 20, 2007)


Subject: Engine Coolant Consumption or Coolant Leak (Inspect For Material Degradation/Replace Intake Manifolds)


Models: 1995-1997 Buick Riviera

1995-1999 Buick LeSabre, Park Avenue

1996-1999 Buick Regal

1998-1999 Chevrolet Lumina, Monte Carlo

1995-1996 Oldsmobile Ninety-Eight

1995-1999 Oldsmobile Eighty-Eight

1998-1999 Oldsmobile Intrigue

1995-1999 Pontiac Bonneville

1997-1999 Pontiac Grand Prix

with 3.8L Engine (VIN K -- RPO L36)

--------------------------------------------------------------------------------

This bulletin is being revised to add to the 1999 model year. Please discard Corporate Bulletin Number 01-06-01-007B (Section 06 - Engine).

Condition
Some customers may comment on excessive engine coolant consumption, or an engine coolant leak near or under the throttle body area of the upper intake manifold.

Cause
Upper intake manifold composite material may degrade around the EGR stove pipe and could result in an internal or external coolant leak.

Correction
•Follow the upper intake manifold removal instructions found in the Engine Unit Repair Section of the Service Information Manual.


•Refer to the arrow in the illustration of the upper intake manifold above. Inspect the inner diameter of the EGR passage for signs of material degradation. Degradation will appear as "pitting" of the composite material in the EGR port passage.
•If degradation of upper intake manifold composite material is found, replace the lower and upper intake manifolds with the following part numbers:
• Gasket Kit, Upper Intake Manifold -- 89017554

• Manifold Kit, Upper Intake -- 89017272

• Gasket, Lower Intake Manifold -- 89017400

• Manifold, Lower Intake -- 24508923

•Follow the lower and upper intake manifold installation instructions found in the Engine Unit Repair Section of the appropriate Service Manual.
•If degradation is not apparent, skip to Step 7.
•Verify the repair.
•If no degradation is found, evaluate the vehicle for other causes of excessive coolant consumption as noted in the Engine Diagnosis Section of the appropriate Service Manual.
Parts Information
Part Number
Description
Qty

89017554
Gasket Kit, Upper Intake Manifold
1

89017272
Manifold Kit, Upper Intake
1

89017400
Gasket, Lower Intake Manifold
1

24508923
Manifold, Lower Intake
1


GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.

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