Gaskets and seals are the simplest and yet most misused parts of an internal combustion engine. People often keep on driving their cars with worn out gaskets without realizing the potential damage to the engines. A car can practically run with faulty gaskets and seals for days but the time will come when it will stall completely.
A gasket is usually a sheet of jointing material placed between two metal surfaces to make them liquid-tight or gas-tight when they are fixed together. The function of a seal or oil seal is similar to that of a gasket; these are usually rubber rings fitted at either end of the crankshaft, in shock absorbers, and in front forks of a motorcycle.
The function of gaskets and seals is to prevent steam, gas or oil from escaping. A simple example is the rubber washer used in a water tap. A worn out washer will let the water drip however hard you try to close the tap. It is easy to imagine what should happen if there are no gaskets and oil seals or if they are worn out. The steam and gas will escape and oil will leak, affecting the performance of the equipment.
Gaskets have great many applications in high-pressure steam systems, internal combustion engines, diesel generating sets, submersible pumps, electric motors, and all types or rotary machines. The most basic of gaskets are produced from special gasket paper. Other materials vary according to the applications but those include silicone, rubber, metal, cork, felt, neoprene, graphite, Teflon and plastic polymers.
A typical internal combustion engine requires a number of gaskets and seals. It is hard to distinguish between the two but gaskets are fitted between two mating surfaces, for example, cylinder head, cylinder cover, valve cover, oil pan, exhaust manifold, exhaust flange, thermostat, carburetor, water pump, etc. Oil seals are fitted at points where oil or gas pressure is tremendous, for example, oil pump, valve stems, timing case, spark plug tubes, exhaust end pipe, valve cover bolts, crankshaft ends, camshaft ends, bearings ends, etc.
If you want optimum performance from your car's engine as well as to maintain its clean 'factory look', immediately replace faulty gaskets and seals.