Results Of Incorrect Operation
• | A plugged positive crankcase ventilation (PCV) valve
(3) or hose (2, 4) may cause the following conditions: |
- | Stalling, or a low idle speed |
• | A leaking PCV valve (3) or hose (2, 4) may cause the following conditions: |
Functional Test
With these systems, any blow-by in excess of the system capacity, from a badly
worn engine, sustained heavy load, etc., is exhausted into the air intake passages
and is drawn into the engine.
Proper operation of the crankcase ventilation system depends upon a sealed
engine. If oil sludging or dilution is noted and the crankcase ventilation system
is functioning properly, inspect the engine for a possible cause. Correct any problems.
If an engine is idling rough, inspect for a clogged crankcase ventilation
valve, a dirty vent filter or air cleaner element, or a plugged hose. Replace any
components as required. Refer to the following procedure:
- Remove the PCV foul air tube from the PCV valve.
- Operate the engine at idle.
- Place your thumb over the end of the PCV valve in order to check for
a vacuum. If there is no vacuum at the valve, check for the following items: