During Engine Oil Service a Small O-Ring Is Found in the Oil Filter Housing. No customer complaint has been received. During the scheduled engine oil service, the technician notices a black rubber o-ring lying on the bottom of the engine oil filter housing. The o-ring has been dislodged from the non-return valve inside the engine oil filter housing. No subsequent engine damage occurs from the dislodged o-ring. Engine oil filter housing (1) Rubber o-ring (2) The material dimensions of the rubber o-ring are not satisfactory, allowing it to become dislodged from its installation location.