Turbocharger: Testing and Inspection
SYSTEM INSPECTION1. Test drive vehicle under heavy acceleration and listen for noise from turbocharger. Turbocharger should produce a smooth whistle under boost conditions. If any roughness is heard, proceed to TURBOCHARGER INSPECTION in this article.
Checking Boost Pressure:
2. Disconnect hose from wastegate actuator, and using enough hose to reach passenger compartment, connect pressure gauge to turbocharger fitting.
3. Test drive vehicle under heavy acceleration and observe gauge. Pressure should be 5 to 12 psi. If pressure was above desired results, proceed to WASTEGATE INSPECTION in this article. If recorded pressure was low, proceed to WASTEGATE INSPECTION and INTERCOOLER INSPECTION in this article.
TURBOCHARGER INSPECTION
1. Remove turbocharger.
Axial Play Checking:
2. Visually check turbine and compressor wheels for cracks, chips or any other damage.
3. Visually check for oil leakage around turbine seal and for oil in the engine side of the compressor housing.
4. Turbine wheel should spin freely without noise or friction.
5. Using a micrometer check axial play.
Measured play should be 0.0005 - 0.0036 in (0.013 - 0.091 mm).
Replace turbocharger assembly if any faults are found.
WASTEGATE INSPECTION
1. Move wastegate valve to check for sticking or binding.
Wastegate Stroke Measurement:
2. Using a micrometer, check wastegate actuator stroke with pressure applied to diaphragm.
Result should be: 0.0150 in (0.38mm) at 11 to 13 psi (78 to 88 kPa).
Replace turbocharger assembly if any faults are found.
WARNING: Do not apply more than 13 psi (88 kPa) to actuator diaphragm.
WASTEGATE SOLENOID
1. Disconnect wastegate solenoid electrical connector.
Solenoid Test:
2. Apply battery voltage to wastegate solenoid as shown.
3. Check for continuity between vacuum ports.
Continuity should exist.
If desired results are not achieved, replace wastegate solenoid.
INTERCOOLER INSPECTION
1. Inspect intercoolers for damage to the tanks or fins. If cracks or dents or found replace the affected unit.