GM Service Manual Online
For 1990-2009 cars only

Concern

Action

External oil leak

Inspect for any of the following conditions:

    â€¢ Plugged positive crankcase ventilation (PCV) valve
    â€¢ Damaged or incorrectly installed PCV valve or PCV valve O-ring
    â€¢ Excessive crankcase pressure

Rough Idle

Inspect for any of the following conditions:

    â€¢ Plugged PCV valve
    â€¢ Plugged or kinked PCV valve O-ring
    â€¢ Leaking damaged PCV valve or PCV valve O-ring

Stalling or slow idle speed

Inspect for any of the following conditions:

    â€¢ Plugged PCV valve
    â€¢ Leaking damaged PCV valve or PCV valve O-ring

High idle speed

Inspect for a leaking damaged PCV valve or PCV valve O-ring.

Sludge in the engine

Inspect for a plugged PCV valve.