PCV system

The PCV system uses intake manifold vacuum to ventilate blow-by vapors from the crankcase and return the vapors to the intake manifold for combustion. The PCV valve varies the amount of blow-by vapors returned to the intake manifold based on available engine vacuum. The PCV valve also prevents entry of combustion backfiring into the crankcase. The PCV valve is serviced as part of the crankcase vent oil separator.