Blow-by gas separator

A crankcase ventilation oil separator for an internal combustion engine comprising a housing defining an oil separation chamber having a blow-by inlet receiving crankcase blow-by gasses from the associated engine, a separated gas return for delivering gasses from which oil has been separated to an induction system of the associated engine, a separated oil receiving chamber formed at a lower portion of said oil separation chamber receiving oil separated from the crankcase blow-by gasses, an oil return passage formed in a lower portion of said separated oil receiving chamber communicating with the crankcase of the associated engine, said oil return passage including a flow opening for providing the communication with the crankcase of the associated engine, and a pressure responsive flow control valve controlling the flow through said flow opening comprising a first valve element disposed on one side of said flow opening and a second interconnected valve element disposed on the other side of said flow opening, said first valve element restricting said flow opening when the pressure in said oil separating chamber is greater than the pressure in said oil return passage, said second valve element restricting said flow opening when the pressure in said oil return passage is greater than the pressure in said oil separating chamber.