An intake manifold gasket is a malleable material that is set between the air intake manifold, the cylinder heads and the block in a gasoline powered internal combustion engine. Intake manifold gaskets prevent leakage of air or the air-fuel mixture by sealing the gap between these various metal engine parts.
The intake manifold operates as a sort of plenum, drawing and funneling air and fuel from the carburetor to the cylinders or, in fuel injected engines, just air to the injection ports. A measured amount of air is sucked from the manifold into the vacuum and thereby injected, along with fuel, into the cylinders to be ignited. The air drawn into the cylinders will suddenly hit the shut door of the intake valve and will rush back upon itself causing a wave of high pressure in the manifold runners. The intake manifold gasket must be able to withstand this constant change in air pressure.
A leaking intake manifold gasket will contribute to poor fuel economy, higher emissions and poor engine performance. The typical automobile engine runs on a stringently controlled air-fuel ratio. The intake manifold gasket, in conjunction with such mechanisms as the intake valve and the fuel injector computer, maintains that ultimate ratio. Should any of these components begin to fail, the vehicle’s gas mileage decreases, its gaseous emissions increase and eventually the engine stops running altogether.
The proper distribution of air into the cylinders is obviously very important to the efficient operation of the engine. All gasket material has to be pliable and must be installed using a special gasket cement/sealant to ensure that the gasket remains correctly seated. Proper removal and replacement of the intake manifold gasket can be done by a fairly knowledgeable do-it-yourselfer. It should, however, be performed by a qualified mechanic who has the proper equipment and training to do the job quickly and inexpensively.
The intake manifold gasket is a critical yet comparatively delicate piece of equipment. Essentially, it is the weak link in the system. Today, there are thicker and sturdier intake manifold gaskets manufactured that will better handle another essential function of the intake manifold gasket, keeping heat generated through the engine block from creeping into the air intake manifold. Fuel ignites best with cooler air. The thicker intake manifold gasket is ordinarily used in turbocharged engines, but has been modified to work well for heat management in non-turbocharged engines as well.
Source: www.wisegeek.com
