GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Restricted oil supply hose

Inspect for restricted turbocharger oil supply hose.

Spun camshaft bearing

  1. Remove the oil supply hose. Refer to Turbocharger Oil Feed Pipe Replacement.
  2. Visually inspect for correct alignment of the camshaft bearing oil hole.
  3. Rotate the engine 1/2 turn and inspect the camshaft bearing oil hole for movement, indicating a spun camshaft bearing.