Oil Backflow Prevention Kit 964 1989-94 - Prevents Smoking at Startup

Oil Return Stop Kit – Prevents Oil Backflow and Smoke Development

Our Oil Return Stop Kit prevents engine oil from flowing back from the oil tank into the engine (suction side) when the engine is turned off – especially during extended downtimes.

All Porsche 911, 964, and 993 models (built between 1966 and 1998) share the same issue: After shutting off the engine, the remaining oil in the tank creates pressure (hydrostatic pressure) on the oil pump. This causes oil to flow backward through the pump and accumulate in the engine housing. On the next startup after a long standstill, this leads to excessive smoke development.

Our Oil Return Stop Kit prevents oil from flowing back into the engine after shutdown. As a result, no excess oil remains in the engine housing – eliminating smoke at startup.

Kit contents:
Oil return stop valve with a precisely fitted oil suction hose (oil tank to the engine)
4 hose clamps

Important notice:
The oil hose must be installed without kinks! A kinked hose can cause severe engine damage.

Please make sure to check the part number for the correct model when ordering.