Exhaust System: Turbocharger: Inspection

Fig 1: Inspect Compressor Housing for Impeller Rubbing Condition

Courtesy of DAIMLERCHRYSLER CORP.

Visually inspect the turbocharger and exhaust manifold gasket surfaces. Replace stripped or eroded mounting studs.

1. Visually inspect the turbocharger for cracks. The following cracks are NOT acceptable:
   • Cracks in the turbine and compressor housing that go completely through.
   • Cracks in the mounting flange that are longer than 15 mm (0.6 in.).
   • Cracks in the mounting flange that intersect bolt through-holes.
   • Two (2) Cracks in the mounting flange that are closer than 6.4 mm (0.25 in.) together.
2. Visually inspect the impeller and compressor wheel fins for nicks, cracks, or chips. Note: Some impellers may have a factory placed paint mark which, after normal operation, appears to be a crack. Remove this mark with a suitable solvent to verify that it is not a crack.
3. Visually inspect the turbocharger compressor housing for an impeller rubbing condition. See Fig 1. Replace the turbocharger if the condition exists.
   Fig 2: Measuring Turbocharger End Play

   Courtesy of DAIMLERCHRYSLER CORP.

   1 - DIAL INDICATOR

4. Measure the turbocharger end play:
   • Install a dial indicator (1) as shown in illustration . Zero the indicator at one end of travel. See Fig 2.
   • Move the impeller shaft fore and aft and record the measurement. Allowable end play is 0.026 mm (0.0001 in.) MIN. and 0.127 mm (0.005 in.) MAX. If the recorded measurement falls outside these parameters, replace the turbocharger assembly.
   Fig 3: Measuring Turbocharger Bearing Radial Clearance

   Courtesy of DAIMLERCHRYSLER CORP.

   1 - FEELER GAGE

5. Measure the turbocharger bearing radial clearance:
   • Insert a narrow blade or wire style feeler gauge (1) between the compressor wheel and the housing. See Fig 3.
   • Gently push the compressor wheel toward the housing and record the clearance.
   • With the feeler gauge in the same location, gently push the compressor wheel away from the housing and again record the clearance.
   • Subtract the smaller clearance from the larger clearance. This is the radial bearing clearance.
   • Allowable radial bearing clearance is 0.076 mm (0.003 in.) MIN. and 0.102 mm (0.040 in.) MAX. If the recorded measurement falls outside these specifications, replace the turbocharger assembly.