Is this a common thing on the a4 . Mine is a 2.0 tdi
Speak to Adam at Tdi turbo's on the tdocuk's forum, overhauled mine and upgraded it at a very reasonable price
I have 2 turbo's for bkd engines atm if of us, one is hybrid brand new in box & other is used removed from working car for an upgrade, cleaned all vanes & mechanisms aswell.
Doubt it very much, however if you can be bothered to check have a look at the tdocuk.com forum and ask, turbo knowledge is massive on there sorry I cannot help