GM Service Manual Online
For 1990-2009 cars only

Condition

Action

Important: Oil in the turbocharger air inlet duct,oil on the compressor wheel, and oil throughout the charge air cooler system is normal with a closed PCV system. Do not attempt repairs for this condition.

Restricted air system

Inspect for clogged air filter element or restricted air inlet system.

Restricted exhaust system

Inspect for a restricted exhaust.

Leaking exhaust system.

Inspect for exhaust manifold leaks.

Poor oil drainage from turbocharger

Inspect for restricted turbocharger oil drain pipe.

Restricted crankcase ventilation system

Inspect for restricted crankcase ventilation system.

Worn internal engine components

Inspect for excessive blowby or engine oil consumption.