Crankcase Ventilation System Description: Operation
WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The only flow through the oil/air separator is the combustion blow-by, as there is no fresh air inlet to the crankcase. The primary flow of blow-by into the separator is through the openings inside the valve rocker arm cover. The oil/air separator causes oil, which may be suspended in the blow-by gases, to be separated and drain back to the crankcase. The blow-by gases are then drawn into the air cleaner outlet resonator by normal engine vacuum and burned in the combustion process.