Positive Crankcase Ventilation: Description and Operation

Positive Crankcase Ventilation Control System Operation

A Positive Crankcase Ventilation (PCV) control system is used to provide complete use of the crankcase vapors. Fresh air from the air cleaner is supplied to the crankcase. The fresh air is mixed with blowby gases which then pass through a vacuum hose into the intake manifold. Periodically inspect the hoses and the clamps. Replace any crankcase ventilation components as required.
A restricted or plugged PCV hose may cause the following conditions:
- Rough idle
- Stalling or low idle speed
- Oil leaks
- Oil in the air cleaner
- Sludge in the engine
A leaking PCV hose may cause the following conditions:
- Rough idle
- Stalling
- High idle speed