Originally Posted by willwren
So you're one of the people that got burned by a dealer into replacing the lower intake also? That sucks. Unnecessary expense, unrelated to the problem.
Originally Posted by bill buttermore
My suspicion is that the dealer replaced your lower intake manifold with the newer
design lower that uses a reduced diameter (5/8" ) stovepipe. .
Is it possible that a third explanation for changing the lower intake manifold exists?
In my particular case, I had some etching/pitting on the lower intake manifold gasket
surfaces which mate to the heads. The corresponding gasket surfaces on the heads are just fine,
but then, the heads are made out of cast iron rather than aluminum.
Attached is a link to my dilemma along with a picture of the pitting on my LIM.
As suggested by some of the folks here on this forum, I have used J-B weld to
smooth-up these gasket mating surfaces on the LIM. However, if I was a mechanic at a
Pontiac garage, I donít think Iíd be doing that for a customerí* car. I would think from the Pontiac mechanicí* perspective,
if the condition of the lower intake manifold gasket
surfaces could jeopardize the long term successful sealing of the head gaskets, then
replacement of the Lower Intake Manifold would be required.
After looking at these etched aluminum gasket surfaces, ití* given me a better
appreciation for the value of flushing and changing the cooling systems more often.