Positive Crankcase Ventilation: Description and Operation

Crankcase Ventilation System:

The CCV system is similar to a conventional PCV system, but does not use a vacuum controlled valve. A molded vacuum tube connects manifold vacuum to a fitting on the side of the cylinder head cover. The fitting contains a 2.2 mm orifice that meters the amount of crankcase vapors drawn out of the engine at the cylinder head cover.
When the engine is operating, fresh air enters the engine at the rear of the cylinder head cover through the fresh air hose and mixes with crankcase vapors. Manifold vacuum draws the vapor/air mixture through the metered orifice and into the intake manifold. The vapors are consumed during combustion.