Auxiliary Emission Control Systems: VOLVO: VOLVO: Operation

During idling and slow speed operation, crankcase gases are drawn into combustion chamber through oil filter cap and PCV valves on 6 cylinder or through flame guard and PCV valve on 4 cylinder. During high speed or full throttle operation, crankcase gases are drawn through hose to intake manifold and the excess gases are drawn through the hose to air cleaner. On the Turbo, the crankcase gases are drawn through hose to turbo-compressor intake.

Fig 1: Crankcase Ventilation System (4 Cylinder Models, Except Turbo)

Courtesy of VOLVO CARS CORPORATION