Crankcase Ventilation System Inspection/Diagnosis
Results of Incorrect Operation
A plugged positive crankcase ventilation (PCV) orifice or hose
may cause the following conditions:
| • |
Stalling or slow idle
speed |
| • |
Oil in the throttle
body |
Functional Check
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 throttle body and is drawn into the engine.
Proper operation of the crankcase ventilation system depends
upon a sealed engine. If oil slugging or dilution is noted and the
crankcase ventilation system is functioning properly, check the
engine for a possible cause. Correct any problems.
If an engine is idling rough, inspect for a clogged PCV orifice,
a dirty vent filter, air cleaner element, or plugged hose. Replace
as required. Use the following procedure:
| 1. |
Remove the PCV hose from the
cylinder head cover. |
| 2. |
Operate the engine at
idle. |
| 3. |
Place your thumb over the end
of the hose in order to check for a vacuum. If there is no vacuum
at the hose, inspect for the following items: |
| 5. |
Inspect the PCV orifice in the
cylinder head cover for debris or blockage. |
|
