GM Service Manual Online
For 1990-2009 cars only

Crankcase Ventilation System Diagnosis for Saturn L300/LW300 2001

With this system, any excessive blow-by in system (from a badly-worn engine, a sustained heavy load, etc.) is exhausted into intake manifold and is drawn into engine. A proper operation of the PCV system is dependent upon a sealed engine. If oil sludging or dilution is noted, and PCV system is functioning properly, check engine for other causes and correct as necessary in order to ensure that system functions as intended.