GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

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

Visually inspect for evidence of compressor wheel to housing contact.

If the turbocharger bearings are worn or damaged, inspect for a Turbocharger Lack of Oil Supply.

Intake system leaks or obstructions

  1. With the engine off, pressurize the intake system and inspect for intake manifold leaks.
  2. Inspect for obstructions in the intake manifolds.