Positive Crankcase Ventilation
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
DO NOT remove PCV system from engine. Removal of PCV system will adversely affect fuel economy and engine ventilation and result in shorter engine life.
Positive Crankcase Ventilation (PCV) System cycles crankcase gases back through engine where they are burned. PCV valve regulates amount of ventilating air and blow-by gas to intake manifold and prevents backfire from traveling into crankcase. PCV valve should be mounted in a vertical position. On some applications, PCV system is connected to EVAP emission system. Refer to Vehicle Emission Control Information (VECI) underhood decal.