9-5 SE Sedan (9600) V6-3.0L Turbo (B308) (1999)
To prevent the vacuum from becoming excessive, fresh air is admitted to the oil trap through the large-diameter crankcase ventilation line. The fresh air
comes from the turbo intake pipe.
Overpressure in the intake manifold
The check valve closes and prevents the intake manifold air from going down into the crankcase. The flow of air in the large-diameter line has changed
direction, with the result that crankcase gases pass out of the oil trap's large-diameter connection.
Crankcase gases are sucked into the turbo intake pipe and continue through the turbo and charge air cooler into the engine where the accompanying
hydrocarbons are burnt.