Crankcase Ventilation (CV) System Inspection
• | Test for vacuum at the foul air hose where it connects to the positive
crankcase ventilation (PCV) valve. There should be manifold vacuum present at the
hose. If there is no vacuum, inspect for a plugged hose, leaking hose or a plugged
intake manifold crankcase ventilation vacuum passage. |
• | Plug the end of the foul air hose while the engine is running. Inspect
the hose for any areas that collapse when the end of the hose is blocked. Replace
the hose if it collapses when blocked. |
• | If oil has accumulated in the intake air duct, inspect for the following
conditions: |
- | Plugged intake manifold crankcase ventilation vacuum passage. |
- | Missing or damaged PCV to valve rocker arm cover grommet. |
- | Excessive air leakage past engine gaskets and/or seals preventing a vacuum
condition in crankcase. |
• | Additional items to inspect: |
- | Plugged or leaking fresh air vent hose. |
- | Plugged or restricted passages in the throttle body |
- | Missing, damaged, or leaking; PCV to valve rocker arm cover grommet, valve
rocker arm cover seals, oil pan seal, and all other crankcase seals and sealing areas
for leaks. |
Results of Incorrect Operation
A plugged PCV valve or foul air hose may contribute to the following
conditions:
• | Stalling or a slow idle speed |
• | Oil accumulation in the intake air duct |
A leaking PCV valve or hose may contribute to the following conditions: