S10/T10 P/U 2WD L4-137 2.2L DSL (1984)
Positive Crankcase Ventilation: Description and Operation
Although the function of the crankcase ventilation system is the same for both gasoline and diesel engines, the systems and control valves are different.
Diesel engines use either a Closed Crankcase Ventilation system or Crankcase Depression Regulator to regulate the flow of blow-by gases back into the
engine.
Fig. 76 Typical Closed Crankcase Ventilation (CCV) system. 4 cyl. diesel engines
CLOSED CRANKCASE VENTILATION
This system, used on 4 cylinder diesel engines, consists of a baffle plate oil separator inside the valve cover, PCV valve on the cover, and a hose
connecting the valve and intake manifold, Fig. 76. The baffle plate separates oil particles from blow-by gases and provides an area in the cam cover for
gases to collect. When pressure in the cam cover exceeds intake manifold pressure by a specified amount, the PCV valve opens and blow-by gases are
forced into the intake manifold and drawn into the engine.