Grand Prix V6-3.8L SC VIN 1 (1997)
Positive Crankcase Ventilation: Description and Operation
Crankcase Ventilation Flow
Crankcase Ventilation Valve Location
PURPOSE
A crankcase ventilation system is used to consume crankcase vapors in the combustion process instead of venting them to atmosphere. Fresh air
from the throttle body is supplied to the crankcase, mixed with blow by gases and then passed through a crankcase ventilation valve into the
supercharger inlet.
OPERATION
Primary control is through the crankcase ventilation valve which meters the flow at a rate depending on inlet vacuum.
To maintain idle quality, the crankcase ventilation valve restricts the flow when inlet vacuum is high. If abnormal operating conditions arise, the
system is designed to allow excessive amounts of blow by gases to back flow through the crankcase vent into the throttle body to be consumed by
normal combustion.