Turbo or DV Valve?

[ray-ray]

Hi guys, I have a S3 2002. When i take off it goes pretty well up until about 4500rpm and then it pushes you back in the seat even more. Would that be an expensive turbo issue or would my dv valve just need replacing? My dv has become a bit more vocal lately that would suggest it might be the dv... Any ideas?

[RS ZWEI]

Are you saying when it gets above 4500RPM it pushes you back in your seat, do you mean the performance increases? IE getting on boost?

If your DV is warn it will flutter when releasing pressure, rather than a crisp, shape release.

[ray-ray]

Are you saying when it gets above 4500RPM it pushes you back in your seat, do you mean the performance increases? IE getting on boost?

ya the performance increases like second stage turbo haha.

[Fizz]

Do u have a boost gauge? if so what does it read? Do u still have the stock DV? if so when was it last replaced? if u don't know probably best 2 replace as part of maintenance they not 2 expensive about $80 from the dealers. As RS Zwei said if u DV is stuffed it will flutter like an SSQ BOV rather than a nice somewhat quiet pshhhh sound. Is the car stock?

[ray-ray]

The car is standard and i dont have a boost gauge. Might just replace it and see what happens. Would that explain the extra boost at 4500rpm as well?

[Fizz]

nope, if the dv was infact poked u'd lose boost rather than get extra.
if issue isn't sorted with new dv I'd suggest checking for fault codes using vagcom.
Could also be a sticky Actuator or faulty N75 valve.
If u were overboosting then the ECU should detect it and cut power.

[fuzion]

as fizz mentioned, could be your n75 or maybe even the n249. I would scan the car.

If your diverter is playing up though you will find that you will definitely loose boot or it will fluctuate through the revs.

I'd recommend changing to a Bailey's Diverter (plumback). Dont bother using another stock as they fail as the diaphram colapses after time.

The other thing to check is on the upper manifold your vacuum hose from the FPR. They turn quite brittle and break/leak. I would change this anyhow, it'd cost you like $3 to do so with the vacuum hose from a local auto store. Incredibly common with the 1.8t's.

So for me it would be;

1. Scan Car
2. N249 or n75 check
3. change diverter if you havent already
4. check vacuum hoses

Could be other things though, but they would be the first to check. The next issue could be your MAF.