Turbocharger: Testing and Inspection

ON-VEHICLE INSPECTION:

1. Check for leakage or clogging between air cleaner and turbocharger inlet and between turbocharger outlet and cylinder head.
2. Check for leakage or clogging between the cylinder head and turbocharger inlet and between the turbocharger outlet and exhaust pipe.
3. Using a three-way tee connector, connect a turbocharger pressure gauge to the hose leading to the Fuel Pressure Regulator.

Measuring Turbocharger Boost Pressure With Gauge:

4. On M/T models, with the engine operating at 1,000 rpm in third gear, open the throttle valve fully. Check the reading on the pressure gauge when the engine is over 2,500 rpm.

Standard Pressure: 5.5 - 7.5 PSI (38 - 52 kPa)


5. On A/T models, accelerate from a standing stop in LOW range and fully open the throttle valve. Measure the boost pressure when the engine speed exceeds 3,500 rpm.

Standard Pressure: 4.8 - 6.0 PSI (33 - 41 kPa)

6. If the pressure is less than specified, check the intake air and exhaust system for leakage.
7. If no leakage is found, replace the turbocharger assembly.
8. If the pressure is higher than specified, refer to WASTEGATE ACTUATOR and perform test procedures.

OFF-VEHICLE INSPECTION:

1. Remove turbocharger assembly from engine. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES for proper procedure.
2. Check that impeller wheel turns smoothly. If wheel does not turn or turns with a drag, replace/rebuild the turbocharger.

Checking Impeller Wheel Rotation:

3. Using a dial indicator, measure the axial play through the intake side hole of the turbine.

Measuring Turbine Shaft Axial Play:

Axial Play: 0.0051 in. (0.13 mm) or less

4. If axial play is not as specified, replace/rebuild the turbocharger.
5. Insert the dial indicator through the oil outlet hole and spacer bearing. Set it in the center of the impeller shaft.
6. Moving the impeller shaft in a radial direction, measure the radial play of the shaft.

Measuring Turbine Shaft Radial Play:

Radial Play: 0.0071 in. (0.18 mm) or less

7. If radial play is not as specified, replace/rebuild the turbocharger.
8. Reinstall turbocharger assembly on the engine. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES for proper procedure.