No its not!!!! one end is shut' date=' so the oil is always in contact with the rest of the oil in the engine, so its bound to get hot through heat transfer, when the oil gets to temp the plate opens and oil then flows through the radiator. [/quote'] Fuck me this is getting like punch and judy. Oh no it isn't , oh yes it is Well mine is always open, the oil flows through the rad as soon as the engine is started, it gets warm. End of.