Positive Crankcase Ventilation: Testing and Inspection

Positive Crankcase Ventilation System:

[1][2]PCV FUNCTIONAL TEST

1. With engine idling, disconnect the regulating orifice from the [1][2]PCV hose. If orifice is not plugged, a hissing sound will be heard as air passes through it, and a strong vacuum should be felt when a finger is placed over the inlet.
2. Reinstall the regulating orifice, then remove crankcase inlet hose from the valve cover. With engine idling, loosely hold a piece of stiff paper (such as a parts tag) over the opening in the rocker arm cover. After allowing about a minute for the crankcase pressure to reduce, the paper should be drawn against the opening in the rocker arm cover.
3. If the system passes the above tests, no further service is required. If not, replace the regulating orifice and recheck the system.
4. With a new regulating orifice installed, if the paper is not drawn against the crankcase inlet air cleaner opening with considerable force, it will be necessary to clean the passage in the intake manifold. Also, the [1][2]PCV hose will have to be cleaned or replaced.