Whining noise

[Eric6014]

I've been getting a high pitched whining noise the past few weeks. Might just be the weather getting cold, but I had the same noise about a year ago right before I blew my turbo. I doubt it's the turbo this time since the new one only has few thousand miles on it. The sound gets higher pitched with increased RPM's and is only noticeable in low gears. Sounds like a Honda in reverse. I thought it might be the trans but it makes the same sound in neutral. Any ideas what it could be?

 

[ROH ECHT]

Would be helpful to hear it...I am imagining a high pitched whistle.
Have you checked if the PCV is shot?
While at idle, check this hole to see if it has suction or air coming out.
Or have someone rev it and listen to it.
It could also be a leak in the air inlet between the turbo and intake manifold.

 

[Eric6014]

Would be helpful to hear it...I am imagining a high pitched whistle.

Thanks for the reply. I'll try and post some video. It's less of a whistle and more of a whine. But I wouldn't be surprised if it was the PCV. I will check that out. If it was an air leak would I be seeing a decrease in boost?

 

[ROH ECHT]

Yes....most common issue associated with hearing a high pitched sound or squeal is a leak in the boost(air inlet) plumbing or a failed N249-DV(diverter valve). Could also be the DV. After the PCV is checked...You'll need to check all the connections for the boost plumbing. If they are OK, then remove the N249-DV and inspect its diaphragm or piston. There are about nine or ten connections in the boost plumbing...five or six of those are the clipped connectors the rest are clamped. The clipped connectors are more likely to be where they leak. They become unclipped or their seals are in need of replacing.

Do you know where all of these are?
Page 14 here shows the plumbing:
http://www.volkspage.net/technik/ssp/ssp/SSP_337.pdf

If you notice an oily residue at a point of connection...it likely needs a new seal (charge pipe o-ring).

At 2:55 this shows how to disconnect the clips to access the coupler seals:

 

[Eric6014]

Update on this. Or more like no update. I injured my hand and had to have surgery not long after posting this, so I won't be getting under the hood any time soon. I will post an update once I'm able to check it out.