GM Service Manual Online
For 1990-2009 cars only

Condition

Action

Some whine noise is normal. Compare to a known good vehicle.

Leaking charge air cooler/pipes/hoses

Inspect for leaks in charge air cooler/pipes/hoses.

Worn turbocharger bearings

    •  Inspect the turbocharger bearings. Refer to Turbocharger Lack of Oil Supply .
    •  If the turbocharger bearings are worn or damaged, repair or replace the turbocharger.

Intake system leaks or obstructions

Inspect for leaks or obstructions in the intake manifolds.