The ability of the Oldsmobile Seals and Gaskets to contain the contents of the liquids in the engine is why it can last for many years. Without the seals and gaskets in place, oil, coolant and even the compression of the cylinders would not be able to be maintained for any period of time on your Oldsmobile.
The material the seals and gasket are made from have to be constructed to withstands the stresses that this material will be exposed too on a constant basis when they are in place on your Oldsmobile. This is why the materials the seals and gaskets used on your vehicle will include not only silicones but polymers, cork and composite materials. This makes it possible to seal the junctions of either flat surfaces like the head gaskets or round areas like the valve seals.
The inspection of the many Oldsmobile seals and gaskets is very different than all other components on your vehicle. The drive belts can be visual inspected because the entire surface area of them can be seen. This is the same for the many different coolant hoses. When it comes to the many gaskets and seals that are used in the junctions of component, their entire surface cannot be visible unless the components that are joined are taken apart on your Oldsmobile.
The only indication that an owner of a vehicle will know if the seals or gaskets are leaking is by visual appearance at the edge of the joint that is being sealed. If a valve cover gasket is leaking, oil will be seen emanating from the joint as an example. This is why these components are not caught before they have a rupture and a very good reason for periodical inspections of your engine should occur so when one goes, it can be noticed in a very short allotment of time.