Overboost Valve: Testing and Inspection

Overrun shut-off valve, checking
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required





^ V.A.G 1390 Hand vacuum pump

Test conditions
^ Reduced performance or load change shudders

Test sequence

Note: The overrun shut-off valve is located in front of the turbocharger. It is opened by vacuum pressure during the overrun phase and at idling speed.





- Connect hand vacuum pump V.A.G 1390 to vacuum connection on overrun valve.
- Operate hand vacuum pump. Overrun valve must open in direction of arrow.
- Operate vent valve on hand vacuum pump. Overrun valve must close.
Overrun valve does not open or close, replace valve.

Note: The overrun shut-off valve connections are secured with screw-type clips.