ENGINE AND EMISSION CONTROL ± Emission Control System
PCV valve
PCV valve
17-8
CRANKCASE EMISSION CONTROL SYSTEM
GENERAL INFORMATION
The crankcase emission control system prevents
blow-by gases from escaping inside the crankcase
into the atmosphere.
Fresh air is sent from the air cleaner into the
crankcase through the breather hose. The air
becomes mixed with the blow-by gases inside the
crankcase.
The blow-by gas inside the crankcase is drawn into
the intake manifold through the positive crankcase
ventilation (PCV) valve.
The PCV valve lifts the plunger according to the
intake manifold vacuum so as to regulate the flow
of blow-by gas properly. In other words, the blow-by
gas flow is regulated during low load engine
operation to maintain engine stability, while the flow
is increased during high load operation to improve
the ventilation performance.
SYSTEM DIAGRAM
PCV
valve
Ventilation hose
Breather hose
COMPONENT LOCATION