In case the crankcase of the vehicle engine, the engine oil the oil movable androtating spaces between crankshaft bearings andconnecting rods, integrating the pistons to the crankshaft. Engine oil stores is stored in the lower part of the housing. In some engines with reduced size, such as lawn mowers, the bottom parts of the connecting rod submerged are oil, splashing the casing, to lubricate the internal parts. In drives modern vehicles, the oil pump takes oil from the container for oil andsends it through the oil filter to galleries from which oil lubricates crown bearings, helping various bearings which work in valves - when is not the case, necessary is remont silnika.

In current, typical vehicles, pressurized engine oil from oil galleries moves towards direction critical bearings, andenters through the holes of the key bearings in the crankshaft. From these holes, towards the key bearings, the oil moves by support passages in the center of the crankshaft towards direction holes result in a rod with bearings in order to lubricate the bearings of the andconnecting rods.