Explorer 2WD V6-245 4.0L SOHC VIN E EFI (1997)
Positive Crankcase Ventilation: Description and Operation
OPERATION
The PCV system uses intake manifold vacuum to ventilate blow-by fumes from the crankcase and return the fumes to the intake manifold for
combustion.
The PCV valve varies the amount of blow-by gases returned to the intake manifold based on available engine vacuum. The PCV valve also
prevents the entry of combustion backfiring into the crankcase.