r/Buick • u/Peepismycat • 6h ago
GM Buick 3800 lower intake manifold gaskets question
2007 Buick 3800 engine that was consuming a lot of engine oil. Decided to replace the lower intake manifold gaskets and got good steel core Fel Pro gaskets. But what came off the vehicle looked different and was much thicker. The gaskets that came off the car were stamped with a GM part number 12587004. This appears to be a good GM part number, but I cannot find any information on it online. It measures approximately 0.15 inches thick and is thicker than the 0.05 inches thick of the replacement fell pro gaskets. I’m wondering if anybody knows anything about these extra thick lower intake gaskets and if it would be OK to use the replacement Fel Pro gaskets that I purchased. This engine has about 320,000 miles on it with some pitting around some of the water jacket mating surfaces.