CTS-V V8-6.0L VIN U (2006)
Positive Crankcase Ventilation: Testing and Inspection
Crankcase Ventilation System Inspection/Diagnosis
Crankcase Ventilation (CV) System Inspection
^
Test for vacuum at the positive crankcase ventilation (PCV) dirty air hose where it connects to the vacuum orifice tube in the engine valley cover.
There should be a manifold vacuum present at the hose. If there is no vacuum, inspect for a plugged hose, leaking hose or a plugged intake
manifold passage.
^
If oil has accumulated in the intake, inspect for the following conditions:
^
Plugged vacuum orifice tube in the engine valley cover
^
Plugged, restricted, or leaking PCV dirty air hose
^
Plugged or restricted intake manifold passage
^
Excessive crankcase pressure or blow-by
Additional items to inspect:
^
Plugged or restricted PCV fresh air hose
^
Inspect the valve rocker arm cover, the oil pan, engine front cover, and other sealing areas for leaks
Results of Incorrect Operation
A plugged crankcase ventilation system may contribute to the following conditions:
^
A rough idle
^
Stalling or a slow idle speed
^
Oil leaks
^
Oil accumulation in the intake manifold
^
Sludge in the engine
A leaking hose may contribute to the following conditions:
^
A rough idle
^
Stalling
