So I've had boost surging / fluctuation with my 1.8T AUM and I can't seem to trace the problem.
It doesn't always happen and its always when near wide open throttle, sometimes it happens, other times it doesn't.
In the last year and a bit I've done:
- New Coil Packs + New loom wiring
- New MAF
- N249 + SAI Deleted
- PCV Pipes pretty much all changed.
So after all that the problem still remained and I had the error
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
So I put it down a boost leak. Well today I made a boost leak tester using a tyre stem and baked beans can hooked up to a tyre inflator.
There are no leaks I could find in the system, when pressurised it slowly bled air into the engine and out through the dip stick hole, which I assume is either some air blowing past the turbo oil seals, or the PCV check valve? (I clamped off the pipe from the rocker to the TIP whilst testing)
Next I cleaned the throttle body as apparently this can cause surging as well, it was pretty clean, but I got it immaculate and then calibrated it using VCDS.
End result - Car still surging on boost.
What's next to try?
It doesn't always happen and its always when near wide open throttle, sometimes it happens, other times it doesn't.
In the last year and a bit I've done:
- New Coil Packs + New loom wiring
- New MAF
- N249 + SAI Deleted
- PCV Pipes pretty much all changed.
So after all that the problem still remained and I had the error
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
So I put it down a boost leak. Well today I made a boost leak tester using a tyre stem and baked beans can hooked up to a tyre inflator.
There are no leaks I could find in the system, when pressurised it slowly bled air into the engine and out through the dip stick hole, which I assume is either some air blowing past the turbo oil seals, or the PCV check valve? (I clamped off the pipe from the rocker to the TIP whilst testing)
Next I cleaned the throttle body as apparently this can cause surging as well, it was pretty clean, but I got it immaculate and then calibrated it using VCDS.
End result - Car still surging on boost.
What's next to try?