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Oil pan of a car engine

An oil pan is a component of internal combustion engines . It keeps the engine oil required for lubrication in the engine. It is screwed to the lowest point of the engine, the crankcase , and is usually equipped with an oil drain plug through which the oil can be drained when changing the oil or making repairs.

Oil pans of passenger car engines typically have a capacity of 2 to 8-liter. Although the rumor persists among some motorists that “a little more than MAX on the oil dipstick is not a bad thing” and “the engine will burn up the excess oil”, we strongly advise against filling the oil pan beyond the maximum limit: During operation Otherwise the crankshaft would plunge into the oil with every revolution and over time distribute microscopic air bubbles in the oil. These are so fine that they only diffuse out again very slowly. But if such an air bubble is then in the lubricating film in the cylinder , it expands due to the greater heat present there, bursts and causes reduced lubrication. In addition, foamy oil has significantly impaired flow properties and a reduced lubricating effect when cold. Only sports engines reduce the foam in the oil filter if a more foam- suppressing oil is not used anyway for use in racing. In the event of overfilling, oil can also get into the intake tract via the crankcase ventilation and cause damage to sensors, spark plugs (in gasoline engines), pistons, turbochargers and catalytic converters / particle filters.

Oil pan of an automatic transmission (with deposited oil sludge)

In automatic transmissions with a torque converter, the filter is located inside the oil pan and is always replaced when the oil is changed.

See also

  • Oil dilution , thinning of the engine oil caused by the drag-in of fuels into the lubricating oil of an internal combustion engine


  • Jan Drummans: The car and its technology. 1st edition, Motorbuchverlag, Stuttgart, 1992, ISBN 3-613-01288-X
  • Max Bohner, Richard Fischer, Rolf Gscheidle: Expertise in automotive technology. 27th edition, Verlag Europa-Lehrmittel, Haan-Gruiten, 2001, ISBN 3-8085-2067-1

Web link

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