Positive Crankcase Ventilation: Description and Operation

CCV SYSTEM
This engine is equipped with a Crankcase Ventilation (CCV) system. The system consists of:

Fig. 2 CCV System - 4.0L Engine:

- A fixed orifice fitting of a calibrated size. This fitting is pressed into a rubber grommet located on the top/rear of cylinder head (valve) cover.
- a pair of breather tubes (lines) to connect the system components.
- the air cleaner housing.
- an air inlet fitting.

The CCV system performs the same function as a conventional PCV system, but does not use a vacuum controlled PCV valve.

The fixed orifice fitting meters the amount of crankcase vapors drawn out of the engine.

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