shv2.7T

I have a 2000 MY 96,000 mile 2.7 T, no mods. All regular maintenance done- great car, but requires about 1k/year for maintenance.
For the past 20k or so miles, would hear the high pitched turbo squeal when on boost.
For the past few days, I hear a louder 'whoosh' sound when on boost, probaly on an intermittent basis. I feel no difference in acceleration- still good.
I did search through some prior posts. Can someone in the know tell me how to investigate this please- I am afraid the dealer might take overcharge/mislead me. Feedback appreciated, thanks.

halik

<ul><li><a href="http://youtube.com/watch?v=XSEFUIcgOy0">http://youtube.com/watch?v=XSEFUIcgOy0</a</li></ul>

shv2.7T

Thank you for your quick response. No the one you have posted is more high pitched, like a drill/turbine.
The sound in my car is more like hissing except it is not high pitched- hence likened it a whoosh, and it is brief.

halik

I'd guess you have a boost leak somewhere

donp

<ul><li><a href="https://www.audiworld.com/tech/eng19.shtml">TBB</a></li></ul>

audikillsbmw

any power loss, but it would still be a good idea.

2000 A6 2.7t 6m

In that case, it could be a bad BPV (by-pass valve).

a62.7t4ceo

As for the high pitched turbo squeal without power loss, it could be anything even a lose heat shield vibrating.

shv2.7T

It sound like from 2006 A6 2.7t 6m' reply that this may be a diverter valve problem.
Any idea what i am looking at in terms of cost. Dealer normally charges approx $120/- for ' one hour diagnostics'. Thanks again for all the help.