Boost Solenoid: Testing and Inspection

Boost Pressure System, Checking

Special testers required
^ VAG 1397 A Turbocharger tester

Checking requirements
^ Intake and exhaust systems leak tight
^ Engine oil temperature 80°C minimum

Notes:
^ Boost pressure is measured under full load, while driving on the road or on a dynamometer.
^ 10 seconds maximum duration per measurement.





- Disconnect hose between intake manifold and recirculation valve at intake manifold and using T-piece, connect VAG 1397 A turbocharger tester.
- Select measuring range 1.

Notes:
^ To operate turbocharger tester see operating instructions.
^ Hoses must be connected so there is no possibility of leaks.
^ Ensure pressure hose is not trapped between hood and body

CAUTION: Always use a second technician to take measurements via the VAG 1397A Turbo charger tester when driving on the road.

- Measure boost pressure at Wide Open Throttle
On a dynamometer:
^ In 3rd gear or Transmission Range selection 2 between 3000 and 4000 rpm
On the road test drive:
^ In 2nd gear or Transmission Range selection 1, accelerate vehicle at Wide Open Throttle and hold vehicle between 3000 and 4000 rpm by braking at the same time
- Press memory button "M" on turbo tester and read display. Relative pressure specification: 1.350 to 1.650 bar

If specification exceeded:
- Test Wastegate Bypass Regulator valve N75
^ Check to ensure that flow in hose from turbo to pressure unit (via valve) is not blocked when connector is pulled off.
- Ensure control valve pressure unit is securely mounted on turbo.
- Check charge pressure control valve shaft mounting in turbo for ease of movement.

If corroded together
- Replace turbocharger assembly

If boost pressure not attained:
- Check Wastegate Bypass Regulator valve N75.