Caravan AWD V6-201 3.3L (1991)
Positive Crankcase Ventilation: Description and Operation
Positive Crankcase Ventilation System
SYSTEM OPERATION
The purpose of the PCV system is to reduce hydrocarbon (HC) and carbon monoxide (CO) emissions created by engine blow-by. This system is a
closed crankcase ventilation system that consists of a PCV valve, a hose extending from the PCV valve to the intake plenum, a crankcase inlet air filter,
and a hose connected from the crankcase inlet air filter to the valve cover.
Crankcase vapors and piston blow-by are removed from the engine by manifold vacuum. These gases are drawn through the PCV hose and into the
intake plenum, they mix with the calibrated air/fuel mixture, and get burned and expelled with the exhaust gases. No fresh air enters the crankcase with
this system.