Exhaust gaskets provide a seal on exhaust parts in vehicles to guarantee
that when gases leave the engine, they stay in the exhaust system until
they are expelled into the atmosphere. In the system, when gases exit
the engine, they first travel into the exhaust manifold, which is
attached to the side of the engine and is very hot. From there, gases
travel into the exhaust pipes, through the muffler and catalytic
converter and then finally through the tailpipe and out of the vehicle.
Exhaust gaskets are important utilities in emissions systems. Some vehicles also have headers, which help ease the gas pressure when it builds up in the manifold. In four or eight-cylinder engines, four cylinders use the same manifold to exhaust gases, leading to gas pressure buildup. Headers give each cylinder its own exhaust pipe, and since all the pipes are the same length, it ensures that the gases are released into the collector pipe in equal measure so they do not build pressure. There are gaskets throughout the exhaust system to help ensure that these processes go smoothly. It is important that all of the exhaust gaskets provide a firm, secure seal; otherwise, the gases will leak into other areas. Exhaust leaks make the vehicle produce abnormal noises and can also be extremely dangerous if gases like carbon monoxide leak into the inside of the vehicle.
There are three main types of gaskets in this system: the exhaust manifold gasket, the exhaust flange gasket and header gaskets. The exhaust manifold gasket is located between the engine head and the exhaust manifold. This gasket is designed to withstand the extreme pressures from the cylinders and high temperatures from the gases traveling through it. It is made of metal, typically steel, on the manifold side and often has a fiber material on the engine head side so that the manifold has a bit of moving room against the metal part of the gasket. The exhaust flange gasket, also known as a donut gasket, is located between the catalytic converter and the header pipe. It is made to further improve the flow of the gases through the exhaust system and is similar to the manifold gasket in that it is also typically made of steel and can withstand high temperatures. It can also have jointing made from materials such as rubber, graphite or ceramic fiber. Header gaskets are located between the cylinders' individual exhaust pipes, the manifolds, and the collector pipe; these gaskets help seal any gaps so the exhaust gases can flow through those areas without leaking and eventually exit through the tailpipe. Header gaskets are often made from high-fiber materials with a steel filler built for heat and pressure-resistance. All the types of exhaust gaskets have the joint purpose of getting the gases from the engine through the exhaust system and into the atmosphere and are die-cut to fit the specific needs of each part.
Exhaust Gaskets Informational Video