Boost Pressure, Checking
Boost pressure, checkingCheck these first
- idle setting OK (checking, see repair Group 24)
- knock sensor OK (checking, see repair Group 28)
- engine oil temperature 80°C (176°F) minimum
- connect pressure gage VW 1397 to pressure regulator using T adaptor
- open pressure gage check valve to position A
- start engine and run at idle
- remove harness connectors from CO potentiometer and temperature sensor (in front flange on cylinder head, color code blue)
- accelerate to full throttle
- engine speed must increase periodically and then drop (surges)
- observe pressure gage
- boost pressure must reach 0.6 bar (8.7 psi) at high engine speed
If NO
- check air system for leakage, check bypass setting