I had an extremely poor idle, and thanks to the below threads diagnosed it to a failed PCV valve.
However, on the 3.2 VR6, the PCV arrangement is under the valve cover. Which is under the inlet manifold. Which can't be removed without sliding forward the slam panel. Which can't be done unless you remove the bumper...
Anyway, I read the following threads:
A3 3.2 Perished breather diaphragm - whistling sound from hole in rocker cover
VWVortex.com - Valve Cover problems on MKV R32
My PCV valve replacement on Audi A3 3.2, aka shoot me in the face please
and with a bit of help from this thread: VWVortex.com - TT 3.2 Schrick 268 Cams Install
saved myself 8 hours labour or so at a garage and fixed it.
Simple steps (from memory):
Undo wheelarch screws
Undo front bumper screws and nut
Undo 3 screws on top of bumper
Pull out bumper
Disconnect headlamp washer tube
Disconnect foglight connectors
Disconnect lower coolant hose guide
Remove 8x impact bumper bolts
Insert 4x long bolts in top holes
Remove 3x vertical screws by headlights
Pull front slam panel out slightly to check movement OK
Remove all coilpack plugs
Remove all coilpacks
Take out air intake feed
Remove throttle body
Remove manifold bolts at side
Remove all vacuum hoses on manifold
Remove performance port changeover barrel end-piece
Remove/move all wires connected to manifold
Remove 2x bolts holding dipstick guide in
Remove 9x bolts on front of manifold
Undo all vertical bolts on cam cover (and 2 nuts)
Undo anything connected to cam cover
Remove valve cover
Remove PCV valve from valve cover (torx screws, then lever out)
Remove circular cap from PCV assembly
Inspect rubber diaphragm
Replace rubber diaphragm!
Pics (click for larger):
The bolts I used to move the slam panel ("lock carrier to service position" in VAG parlance):
All the bolts removed:
PCV valve/oil separator assembly:
The innocent looking bit of rubber:
And the reason for the whole business - the whole thing was very perished:
And to quote Haynes - "Assembly is the reverse of disassembly"!
As mentioned, although the PCV/cyclone assembly has a part number (022 103 515 A), it does;t seem to be available separately. However, I can confirm that the rubber diaphragm in the 2.0 TFSI PCV (06F 129 101 N) fits and works perfectly.
Many thanks especially to the user VagPro on this forum. This is not a difficult task, just a bit of a pain - I am very much an amateur and it took me about 7 hours all in, not rushing at all. However, I had all the tools needed and a workshop to use with a lift! Any questions, please ask.