high pitched squealing off throttle when warm.

[bmostert]

I couldn’t find any information other than this post and another one on the VW vortex forums regarding the diaphragm. It was the VW one that found you could use the Mercedes PCV internals instead.

If we can just buy the diaphragm alone even better, as you can for most PCVs.

[bmostert]

Update with Pictures attached. Audi PCV on left Merc on right. Also a picture of the Mercedes part no.

I stripped the diaphragm, cap, and o rings off the Merc PCV and simply fitted them to the Audi PCVs. Car runs perfect again now!