Positive Crankcase Ventilation: Description and Operation

All engines produce small amounts of blow-by gasses which seep past the piston rings and into the crankcase. These blow-by gasses are the result of the high pressure developed within the combustion chambers during the combustion process, and contain undesirable pollutants. To prevent blow-by gasses from entering the atmosphere, while allowing for proper crankcase ventilation, the PCV system is used. The crankcase ventilation system vents the blowby gasses into the intake system to be burned. The system is incorporated into the fuel injection system.