FIRST SAMPLE BULLETIN

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 01-06-01-007A

Date: July, 2001

TECHNICAL

Subject:

Engine Coolant Consumption or Coolant Leak

(Inspect For Material Degradation/Replace Intake Manifolds)

Models:

• 1995-1997 Buick Riviera
• 1995-1998 Buick LeSabre, Park Avenue
• 1996-1998 Buick Regal
• 1998 Chevrolet Lumina, Monte Carlo
• 1995-1996 Oldsmobile Ninety-Eight
• 1995-1998 Oldsmobile Eighty-Eight
• 1998 Oldsmobile Intrigue
• 1995-1998 Pontiac Bonneville
• 1997-1998 Pontiac Grand Prix

with 3.8L Engine (VIN K - RPO L36)

This bulletin is being revised to correct parts and labor operation usage. Please discard Corporate Bulletin Number 01-06-01-007 (Section 6 - Engine/Propulsion System).

Condition

Some owners 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

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

2. 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.

3. If degradation of upper intake manifold composite material is found, replace the lower and upper intake manifolds with the following part numbers:

^Lower Intake - 24508923

^Upper Intake - 17113136 (includes necessary upper intake plenum gaskets) 

^Lower Intake Gasket - 12537197

4. Follow the lower and upper intake manifold installation instructions found in the Engine Unit Repair Section of the appropriate Service Manual.

5. If degradation is not apparent, skip to Step 7.

6. Verify the repair.

7. 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

Parts are currently available from GMSPO.

SECOND SAMPLE BULLETIN

Engine Oil or Coolant Leak (Install New Intake
Manifold Gasket) # 03-06-01-010B - (10/24/2003)

Engine Oil or Coolant Leak (Install New Intake Manifold Gasket)

2000-2003 Buick Century

2002-2003 Buick Rendezvous

1996 Chevrolet Lumina APV

1997-2003 Chevrolet Venture

1999-2001 Chevrolet Lumina

1999-2003 Chevrolet Malibu, Monte Carlo

2000-2003 Chevrolet Impala

1996-2003 Oldsmobile Silhouette

1999 Oldsmobile Cutlass

1999-2003 Oldsmobile Alero

1996-1999 Pontiac Trans Sport

1999-2003 Pontiac Grand Am, Montana

2000-2003 Pontiac Grand Prix

2001-2003 Pontiac Aztek

with 3.1L or 3.4L V-6 Engine (VINs J, E - RPOs LG8, LA1)

This bulletin is being revised to change the model Information. Please discard Corporate Bulletin Number 03-06-01-O10A (Section 06 - Engine).

Condition

Some owners may comment on an apparent oil or coolant leak. Additionally, the comments may range from spots on the driveway to having to add fluids.

Cause

Intake manifold may be leaking allowing coolant, oil or both to leak from the engine.

Correction

Install a new design intake manifold gasket. The material used in the gasket has been changed in order to improve the sealing qualities of the gasket. When replacing the gasket, the intake manifold bolts must also be replaced and torqued to a revised specification. The new bolts will come with a pre-applied threadlocker on them.

Notice

An oil leak may result if the vertical bolts are not tightened before the diagonal bolts.

Diagonal bolts may require a crows foot to tighten.

Tighten

1. Tighten the vertical lower intake manifold bolts (1) to 7 N.m (62 lb in).

2. Tighten the diagonal lower intake manifold bolts (2) to 7 N.m (62 lb in).

3. Tighten the vertical lower intake manifold bolts (1) to 13 N.m (115 lb in).

4. Tighten the diagonal lower intake manifold bolts (2) to 25 N.m (18 lb ft).

Parts Information

Parts are currently available from GMSPO.

THIRD SAMPLE BULLETIN

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 03-06-01-016

Date: May, 2003

TECHNICAL

Subject:
Loss of Coolant, Milky Colored Oil
(Replace Intermediate Intake Gasket)

Models:

2000-2003 Buick LeSabre, Park Avenue, Regal
2000-2003 Chevrolet Impala, Monte Carlo
2000-2003 Pontiac Bonneville
2000-2003 Pontiac Grand Prix
with 3.8L V6 Engine (VIN K - RPO L36)

Built Prior to the VIN Breakpoints shown.

Condition

Some owners may comment on a loss of coolant, coolant odor, having to add coolant or a milky substance on either the oil dipstick or oil fill cap. Additionally, owners may indicate that there are signs of coolant loss left on the ground where the vehicle is normally parked.

Cause

Condition may be due to coolant leaking past intermediate intake or throttle body gaskets.

Correction

Important: The upper intake manifold should not be replaced for a coolant leak condition, unless a rare instance of physical damage is found. Even if the throttle body surface shows a slight warpage, the upper intake should not be replaced unless a drivability concern is noted or a relevant engine DTC, such as a code for an unmetered air leak, is set and the upper intake manifold can clearly be shown as the cause of the concern.

Thoroughly check for any external leaks. If no external leaks are found, then replace the intermediate intake manifold gasket and the throttle body gasket. When changing the throttle body gasket, the nuts that retain the throttle body should be replaced with a new design that improves torque retention. Medium strength thread locker should be applied to the studs before installing the new nuts.

Parts Information

Parts are currently available from GMSPO.

FOURTH SAMPLE BULLETIN

Bulletin No.: 04-06-01-017

Date: May 26, 2004

INFORMATION

Subject:
New Upper Intake Manifold and Gasket Kits

Models:
1995-1997 Buick Riviera
1995-2004 Buick Park Avenue
1996-2004 Buick Regal
1997-2004 Buick LeSabre
1998-1999 Chevrolet Lumina
1998-2004 Chevrolet Monte Carlo
2000-2004 Chevrolet Impala
1995-1996 Oldsmobile Ninety-Eight
1995-1999 Oldsmobile Eighty-Eight
1998-1999 Oldsmobile Intrigue
1995-2004 Pontiac Bonneville
1997-2003 Pontiac Grand Prix
with 3.8L V6 Engine (VIN K - RPO L36)

New upper intake manifold and gasket kits have been released. These new kits will provide the dealer with the ability to get exactly what is necessary for a correct repair. In addition some of the gaskets have been updated to a more robust design. Please reference the part numbers when ordering from GMSPO.