Very weird turbo noises #with audio# - 2.0 TFSI CDNB

[patzii123]

Hello guys.
I hope someone can help me with a problem that bothers me now for WAY too long. I'm willing to spend some $$ for successful (!) help.
It's a whistle / squeak that comes from the turbocharger or near associated parts.
The sound itself is various. Have it about 2 years now.
It does not occur in idle - only under load. IHI Turbocharger.

Heres the soundfile (please listen to everything):
https://clyp.it/bqtlxid5

If I push the gas pedal very carefully it starts later in RPM. If I floor it it starts almost immediately.
I can make the sound start at about 1200 RPM - stays all the way up if i keep accelerating.

Some things i noticed:
Its more quiet when the oem airfilter-box is installed. Much more louder with open airfilter (mushroom). But sound is present in both cases.
I thought the turbo starts at 2200 RPM or something? So why does it occure even at 1200 RPM?
Could it be some loose gasket? Which one? How to check?
Intercooler and associated hoses are not leaking. (checked it with pressure tool)
In the soundfile you can hear something that almost sounds like a short turbo flutter when I step from the gas and quickly accelerate again. Could that be a hint to the issue?
I dont think I have perfomance drop. If the turbine would scratch at the walls of the turbocharger wouldn't I have a big drop in horsepower?

I really hope we can find the issue together. Thanks.
If you need more information about something, please post here !

Soundfile_Turbo.mp3

[Steve Q]

I turbo wine/wistle could be due to failing gaskets or hoses to be honest. Is there any hesitation when the turbo is working? 

Cheers

Steve

[patzii123]

23 minutes ago, Steve Q said:

I turbo wine/wistle could be due to failing gaskets or hoses to be honest. Is there any hesitation when the turbo is working? 

Cheers

Steve

No, I dont think there is none?

[Steve Q]

Thats good because that could be a sign that the blades have started to break off. I'd look at changing the gaskets and hoses first but also looking at getting a diagnostic check carried out. Now I wouldn't normally advise this, but your other option is to leave it alone. I speak from experience, my a6 was a whistle and whine on the turbo and has been like it for 5-7 years with no issues and I have just gone past the 330,000 mile mark today. 

Cheers

Steve

[patzii123]

I'll get my endoscope tomorrow then I can check the turbine itself without the need to disassemble anything.

[patzii123]

Today I checked the turbine with an endoscope because there's a 90 degree turn right before it.
Check out these images: https://imgur.com/a/imOIIMA
Looks like I can check the turbine off the list, right? I dont see any traces or anything.

[Kylet1990]

Hey, sounds like a split in the boost pipe somewhere to me. I'm no mechanic however my friend had an s3 that sounded just like that when the boost pipe split.