Why would I have to have the intake gaskets on my GM vehicle replaced twice in 80,000 miles?
In my opinion leaking intake gaskets on GM vehicles are a symptom and not THE problem. A great many shops simply treat the symptom, that is replace the gaskets. Doing so will all but guarantee an encore performance of the issue. We have done quite a bit of research into the problem. In every case of repeat failure I have found excessively rough or uneven mounting surfaces. This is the machined surface of the cylinder heads and lower intake manifold. In some cases coolant was not replaced [properly] and corrosion has damaged the surface. In other cases the shop damages the surfaces by improper methods. Many times the original machine work is too rough to allow a proper seal. Without smooth [60 micro inch or better] surfaces that are flat, lacking pits, clean and properly assembled, the job will not last. For much more information on leaking intake gaskets see our Detailed Topic section.
