Positive Crankcase Ventilation: Testing: Jeep

Remove PCV valve from grommet in rocker arm cover on 6-cylinder models, or hose on V8 models. Connect valve to PCV valve tester (J-23111). Connect a vacuum gauge to intake manifold vacuum.
NOTE: PCV valve must be in a horizontal position and lightly tapped during tests (holding tester in a vertical position).

Start engine, allow engine to idle. Compare vacuum and tester reading to flow chart. A valve that flows above or below chart specification must be cleaned or replaced. See JEEP PCV FLOW RATES chart.

NOTE: Jeep 6-cylinder PCV valve is colored Yellow for 1978-79 models, Silver for older models.

JEEP PCV FLOW RATES 1

Vacuum (In. Hg)

Flow Rate for 6 Cyl. (Yellow or Silver)

Flow Rate for V8 (Black)

1.34-1.63

1.30-1.90

2.70-3.79

1.21-2.26

3.30-4.39

1.28-2.56

⁽¹⁾	Flow rate given in cubic feet per minute (cfm).