GM Service Manual Online
For 1990-2009 cars only

Concern

Action

External oil leak

Inspect for any of the following conditions:

    • Plugged positive crankcase ventilation (PCV) valve.
    • Plugged or kinked PCV hoses.
    • Damaged or incorrectly installed PCV valve or hoses.
    • Excessive crankcase pressure.

Rough Idle

Inspect for any of the following conditions:

    • Plugged PCV valve.
    • Plugged or kinked PCV hoses.
    • Leaking (damaged) PCV valve or hoses.

Stalling or slow idle speed

Inspect for any of the following conditions:

    • Plugged PCV valve.
    • Plugged or kinked PCV hoses.
    • Leaking (damaged) PCV valve or hoses.

High idle speed

Inspect for a leaking (damaged) PCV valve or hoses.

Sludge in the engine

Inspect for any of the following conditions:

    • Plugged PCV valve.
    • Plugged or kinked PCV hoses.