Turbocharger Cleaning and Inspection

Completely inspect the turbocharger and all other engine components that may cause similar conditions before replacing the turbocharger.

Use the following information to diagnose problems caused by the turbocharger.

The turbocharger is serviced as a complete unit.

IMPORTANT: Oil residue on the turbocharger compressor wheel is normal with a closed PCV system.
1. Remove the turbocharger oil return pipe bolts.
Fig 1: View Of Oil Return Pipe Bolts
Courtesy of GENERAL MOTORS CORP.
2. Remove the turbocharger oil return pipe and gasket.
3. Clean mating surfaces.
4. Inspect for damage to the compressor wheel, compared to a normal compressor wheel.
Fig 2: View Of Compressor Wheel
Courtesy of GENERAL MOTORS CORP.
Fig 3: View Of Damaged Compressor Wheel (Soft Object)
Courtesy of GENERAL MOTORS CORP.
5. Inspect for damage to the compressor wheel, by a soft object.
6. Inspect for damage to the compressor wheel, by a hard object.
Fig 4: View Of Damaged Compressor Wheel (Hard Object)
Courtesy of GENERAL MOTORS CORP.
Fig 5: View Of Damaged Compressor Wheel Blades (Heavy Rubbing)
Courtesy of GENERAL MOTORS CORP.
7. Inspect compressor blades for heavy rubbing.

   Ensure that the following conditions do not exist on the compressor wheel blades:

   • Cracks
   • Bends
   • Erosion of the blades
   • Broken blades
8. Check the housing for signs of rubbing.
9. Install the turbocharger oil return pipe and new gasket.
10. Install the turbocharger oil return pipe bolts.

    Tighten:  Tighten the turbocharger oil return pipe bolts to 21 N.m (15 lb ft).

Fig 6: View Of Oil Return Pipe Bolts
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: If the cooling outlet hose eye bolts were removed, install the longer bolt (1) with two holes, in the top location. Install the shorter bolt (2) in the lower location.
11. Inspect the coolant outlet lines for damage.
Fig 7: View Of Cooling Outlet Hose Eye Bolts
Courtesy of GENERAL MOTORS CORP.
12. Clean the turbocharger inlet duct.
13. Clean the turbocharger inlet duct mating surfaces.
14. Inspect the turbocharger inlet duct for cracks.
15. Inspect the turbocharger inlet duct mating surfaces for damage.
Fig 8: View Of Turbocharger Inlet Duct Inspection Areas
Courtesy of GENERAL MOTORS CORP.
16. Replace the turbocharger inlet duct if any damage is found.

    Tighten:  Tighten the inlet duct clamp to 5 N.m (44 lb in).