A drop in oil pressure can spell disaster at the wrong time. Although most modern BMWs do not have an oil pressure gauge, the DME continually monitors internal pressure and will let you know if there is a problem with the pump.
This anti-drain-back check valve is located in the engine block and keeps oil from draining out of the valvetrain and vanos system after shut down. Over time these can become clogged, particularly if long change intervals are followed, allowing oil to drain out of the upper internal passageways. This can contribute to the notorious start-up rattle and result in premature vanos and valvetrain wear due to poor lubrication during startup. 2 required.
Show More Show Less
