PCV System: Description
Vehicles use crankcase ventilation systems to prevent blow-by gases from reaching the atmosphere. The gasoline system consists of a PCV valve with oil screen, manifold calibrated jet (orifice), air cleaner orifice, and connecting hoses.
Diesel models have a hose from the valve cover to the intake manifold that recirculates crankcase vapors. Turbo diesel models recirculate blow-by gases through a main hose from the valve cover cap to the air filter inlet, and a secondary hose from the valve cover cap to the turbocharger air inlet.