Here'* your answer as to why GM wants to replace your Lower Intake:
Engine Coolant Consumption or Coolant Leak
Originally Posted by brminder
I'm loosing coolant somewhere, and I can see some pooling just below the plastic upper intake manifold in a couple of little valleys. Could it just be the gasket or is it most likely the manifold? ALso, I called the dealer to price it, and they said I should replace the lower intake manifold because it'* been redesigned... the 2 together would be over $500!!!.
What have others done??
(Inspect for Material Degradation/Replace Intake Manifolds) #01-06-01-007A
1995-1997 Buick Rivera
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
All With 3.8L Engine (VIN “K” – RPO L36)
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.
Upper intake manifold composite material may degrade around the EGR stove pipe and could result in an internal or external coolant leak.
1. Follow the upper intake removal instructions found in the Engine Unit Repair Section of the Service Information Manual.
2. 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 the 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.