Crankcase Ventilation System Description: Notes
WARNING: This page is about a different car, the 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 Chevrolet TrailBlazer, and 2004 Buick Rainier. However, it is still accessible from the selected car via links, so may be relevant.
A closed crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. Fresh air from the throttle body is supplied to the crankcase, mixed with blow-by gases, and then passed through a crankcase ventilation pipe/passage into the intake manifold.