Crankcase Ventilation Systems - Domestic: Testing: Jeep

Remove PCV valve from grommet in rocker arm cover on 4 and 6 cylinder models, or from hose behind carburetor on V8 models.
Connect valve to PCV valve tester (J-231 11 or equivalent). Four cylinder valves require an adapter for the tester.
Connect a vacuum gauge to read 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 to idle, compare vacuum and tester reading to flow chart. A valve that flows above or below chart specification must be cleaned or replaced.

Jeep PCV F low Rates ⁽¹⁾

Vacuum (In. Hg)

Flow Rate for 4-Cyl.

Flow Rate for 6-Cyl.

Flow Rate for V8

.....

.0-.20

1.34-1.63

.50-1.00

.....

1.30-1.90

.....

.90-2.00

.....

2.70-3.79

1.05-1.85

.....

1.50-2.50

.....

1.50-2.50

.....

3.30-4.39

.....

1.28-2.56

.....

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