Turbocharger: Testing and Inspection

TURBOCHARGER, CHECKING

Special tools, testers and auxiliary items
- VAG 1397 A Turbocharger tester

Checking conditions
- No malfunctions stored in Diagnostic Trouble Code (DTC) memory
- Perform Output Diagnostic Test Mode
- No leaks from intake and exhaust systems
- Wastegate control line is not blocked, loose or leaking
- No engine or fuel injection mechanical malfunctions, e.g. start of injection, fuel injectors and compression pressure
- Engine oil temperature 89 °C minimum

Checking
The turbocharger and wastegate are an assembly. A faulty turbocharger must be replaced because it is not possible to repair using workshop equipment.

Requirements for proper turbocharger operation and achievement of specified boost pressure:
- No leaks from intake and exhaust systems
- Wastegate control line is not blocked, loose or leaking
- No engine or fuel injection mechanical malfunctions, e.g. start of injection, fuel injectors and compression pressure

Test sequence
- Measure boost pressure under full load, while driving on the road

- Test duration per measurement: 10 seconds maximum





- Disconnect hose (at one end) running between intake manifold -1- and Diesel injection pump -2-
- Using a tee, connect VAG 1397 A turbocharger tester

NOTES:
- To operate the VAG 1397A turbocharger tester see manufacturers operating instructions
- If boost pressure is being measured while driving, a second person must be used to read and operate the turbocharger tester
- Ensure that the pressure hose is not trapped between the hood and the body

- Measure boost pressure at Wide Open Throttle, in 2nd gear (manual) or with Transmission Range selector lever in position 1 (automatic) while simultaneously braking the vehicle to maintain approx 37 mph:

- Specification: (relative pressure) 0.60 to 0.83 bar

If specification not obtained
- Replace turbocharger

If boost pressure is too high and if wastegate control line is not blocked, loose or leaking
- Replace turbocharger because wastegate is faulty (unit must be replaced as an assembly)