Positive Crankcase Ventilation: Description and Operation

CRANKCASE VENTILATION SYSTEM
This engine is equipped with a Crankcase Ventilation (CCV) system. The CCV system performs the same function as a conventional PCV system, but does not use a vacuum controlled valve (PCV valve).

Fixed Orifice Fitting - Typical:

A molded vacuum tube connects manifold vacuum to the top of the right cylinder head (valve) cover. The vacuum tube connects to a fixed orifice fitting of a calibrated size 2.6 mm (0.10 inches). It meters the amount of crankcase vapors drawn out of the engine. The fixed orifice fitting is grey in color. A similar fitting (but does not contain a fixed orifice) is used on the left cylinder head (valve) cover. This fitting is black in color. Do not interchange these two fittings.

When the engine is operating, fresh air enters the engine and mixes with crankcase vapors. Manifold vacuum draws the vapor/air mixture through the fixed orifice and into the intake manifold. The vapors are then consumed during engine combustion.