The oil pan,
normally made of thin sheet metal or aluminum, bolts to the bottom of the engine block. It
holds a supply of oil for the lubrication system. The oil pan is fitted with a screw-in
drain plug for oil changes. Baffles may be used to keep the oil from splashing around in
The sump is
the lowest area in the oil pan where oil collects. As oil drains from the engine, it fills
the sump. Then the oil pump can pull oil out of the pan for recirculation.