Golf 2008 ed30 - fluctuating whistle sound when WOT and under boost

[SyntaxTerror]

Hey gents,

So, after having my Ed30 sorted out and mapped (stage 1 APR), it was awesome for a few days. Suddenly last week, i noticed a loud whistling noise on full-boost. Concerning.
The best way i can describe the sound is like a fluctuating whistling boost sound. Almost sounds like very high pitched turbo-flutter, but persistent while on hard boost. Terrified that my turbo might be dying.
The sound is coming from the passengers side of the engine bay.

The performance feels a little down from just after the map, but this might be the car learning the new map, or me learning the map, but i can no longer spin the wheels in the dry when flooring it in second from 3k (previously did this in 4th at 3k!!) with the traction control off.

So, i've done a quick log in 3rd gear using the Boost and Fuelling set shown here: http://www.goapr.com/support/datalogging.php - sadly my vag-com doesn't seem to support turbo mode so the resolution is a bit low.
Car is running on v-power and the 98ron APR map. Everything else bar the APR stage 1 is standard.

Results: http://pastie.org/4407865 <-- you can hit download on the right and just rename .txt to .csv, or copy and paste it into a file. Or you can assimilate the raw csv data in your mind.

I really don't know what this data should look like for a stage 1 APR ed30 (nor really for standard), but these are the thoughts i had:
* Looks like the turbo eventually gets to the requested pressure, but might be a little lower than it should be/taking a little longer (might be normal)
* N75 is diverting a LOT of air into boost early on (this could be normal for stage 1 APR!)
* Weird rail pressure fluctuation at 6k rpm?

I'm going to book the car into the guys at tuningwerkes again at the end of a week to take a look, but any advice in the mean-time would be ace!

Thanks you lot!

[bacillus]

Failing DV??

[SyntaxTerror]

Failing DV??

Yeah, i thought this too. Could be, but the DV was fine literally about 2 weeks back, and it's the revision G (it's already had one fail once) which i hear is a lot tougher.

Could have gone again i suppose, i'll try and have a peek tomorrow if i get a chance. Boost still hitting its peak eventually (going by the logs) and i imagine a tear in the diaphragm would widen quickly and loose a lot more boost.

[edd666999]

I had a loud fluctuating whistling kind of high pitched sound on boost...its wasnt good news and had to swap turbo (k03 --> k04) My symptoms were not achieving requested boost 3500rpm +

[vag12]

This happened to mone other day but might be different from yours, Check the intercooler pipes to see if its clipped off

[keano]

It won't be the actuator controlling boost levels will it? If I give it beans in a higher gear. Eg. Foot down @ 40 when in 5th my actuator makes a real racket.

Give dave (pdt) a shout on here mate