Automobile

Without proper lubrication, the heat and friction created by the rapid movements of the engine's parts would quickly cause it to fail. The lubrication system of an automobile acts to reduce engine wear caused by the friction of its metal parts, as well as to carry off heat. At the bottom of the engine is the crankcase, which holds a supply of oil. A pump, powered by the engine, carries oil from the crankcase and through a series of passages and holes to all the various parts of the engine. As the oil flows through the engine, it forms a thin layer between the moving parts, so that they do not actually touch. The heated oil drains back into the crankcase, where it cools. The fumes given off by the crankcase are circulated by the PCV (positive crankcase ventilation) valve back to the cylinders, where they are burned off, further reducing the level of pollution given off by the automobile.