What is the purpose of the oil pan in an automotive engine?

Oil pans are a major engine cooling system parts. They are usually constructed of thin steel and shaped into a deeper section to fully perform its function. It is also where the oil pump is placed. When an engine is not running or at rest, oil pans collects the oil as it flows down from the sides of the crankcase. In other words, oil pans that are mounted at the bottom of the crankcase serves as an oil reservoir. Engine oil is used for the lubrication, cooling, and cleaning of internal combustion engines.

At the bottom of the pan is the oil drain plug that can be usually removed to allow old oil to flow out of the car during an oil exchange. After the used oil drains out, the plug is screwed back into the drain hole. Drain plugs are often made with a magnet in it, collecting metal fragments from the oil. Some contains a replaceable washer to avoid leakage caused by corrosion or worn threads in the drain hole.

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