Functional Check

With this system, any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted through an orifice located at the bottom of the intake manifold. The orifice is connected, by a channel through the body of the intake manifold, to a port located underneath the throttle body assembly. The excess blow-by is then drawn into the engine through the intake manifold.

Proper operation of the crankcase ventilation system depends upon a sealed engine. If oil slugging or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for a possible cause. Correct any problems.

If an engine is idling rough, inspect for a clogged PCV orifice, a dirty vent filter or air cleaner element. Replace as required. Use the following procedure to inspect for a clogged PCV orifice:

1. Turn OFF the engine.
2. Remove the throttle body assembly.
3. Place hand vacuum pump in PCV port. Seal gap between port and pump hose. Operate pump. If vacuum is created, an obstruction may exist in the PCV orifice or somewhere in the PCV vent channel. Operating the vacuum pump may dislodge the obstruction. If not, inspect PVC orifice for debris or blockage.