GM Service Manual Online
For 1990-2009 cars only

This crankcase ventilation system does not use a PCV valve. The system uses a separator to vent the engine and separate the vapors from the oil. Returning the oil to the crankcase and the vapors to the engine to be reburned. A plugged oil/air separator or hose may cause:

    • Oil leaks due to high crankcase pressure.
    • Sludge in the engine due to inadequate separating of crankcase vapors.