What would be the symptoms?

 

If the CCV diaphragm fails (ruptures or tears) you'll probably get a check engine light due to a vacuum leak which can cause engine misfires at idle, lean air-fuel mixture, hard engine start, or rough engine idle. Possible fault codes would be fuel trim (system lean/system rich) and/or idle speed regulation; e.g. P2279(1), P0507(2) or possibly system too lean P0171(3) and P0174(4).

(1) http://wiki.ross-tech.com/wiki/index.ph ... 279/008825
(2) http://wiki.ross-tech.com/wiki/index.ph ... 507/001287
(3) http://wiki.ross-tech.com/wiki/index.ph ... 171/000369
(4) http://wiki.ross-tech.com/wiki/index.php/16558/P0174

Evidently there's two indicators that the diaphragm has failed you can check without any tools -

1.) An "oil filler cap" test - if you have difficulty pulling off the oil cap while the car is running, the diaphragm is most likely defective.

2.) There's a small hole on the back of the valve cover just above the crankcase intake hose. The hole is there to allow the diaphragm to move with little resistance. If you hear a whistle coming from this location and you put your finger over it and it stops, then it's the diaphragm.

As you can see in the pictures below, in normal operation, the crankcase vents into the COS, pass through the PCV and out to the intake manifold. When the diaphragm fails, air leaks through the outside air inlet.

 

Though I havent bought one, you can get a replacement part - just not from Audi!

https://www.rkxtech.com/collections/eng ... -diaphragm

 

For anyone who wants to attempt this, here's a DIY with photo and workshop instructions. Be aware you will need to replace all the applicable seals and gaskets associated with this effort. Be sure to note the torque values as the Intake Manifold is plastic, so you don't want to crank down too hard on the bolts or you'll risk cracking it.

Here are some pictures of the Cylinder Head Cover removal procedure, step-by-step, to gain access to the CCV. You'll note in this link, he removes the Engine Under Pan and drains the coolant, but this isn't mentioned in the workshop manuals that have been linked below so I'm not sure if these steps are necessary if you're just removing the Cylinder Head Cover.

Couple of links here that show how to get this job done -
https://forums.vwvortex.com/showthread. ... ms-Install
https://forums.vwvortex.com/showthread. ... he-3-6-VR6

Related workshop manuals - A big shout-out to forum Member 'MT-V6' for these workshop pages. [smiley=thumbsup.gif]

View attachment Throttle body - removing and installing (1).pdf
View attachment Intake manifold - removing and installing (1).pdf
View attachment Cylinder head cover - removing and installing (1).pdf
View attachment Intake manifold - exploded view (1).pdf
View attachment Cylinder head - exploded view (1).pdf
The replacement CCV kit can be purchased from RKX Tech (- thanks Veeeb! -) for around $30. I've included a link to their YouTube video on how to remove the COS and replace the CCV diaphragm -

CCV Kit - https://www.rkxtech.com/products/36-pcv-diaphragm
DIY Instruction video - https://www.youtube.com/watch?v=PmI-oH8 ... e=youtu.be

For reference, I found this on a VW forum for the same V6 3.2 engine. Seems this is across the VAG line for this particular engine.

https://forums.vwvortex.com/showthread. ... on-MKV-R32

 

Evening all does the old pcv diaphragm in the rocker cover need removing if you fit the aftermarket item surely it will fall to pieces or degrade and break up?

 

Short answer is yes, it should be removed. But since you'll have to replace the chain and tensioners at some point anyway, you can wait to remove the diaphragm when you have the valve cover off. At which point you can either remove it and replace it and go back to the original breather. Or just remove it and stick with the non-OEM version.

https://www.ttforum.co.uk/threads/how-to-3-2-vr6-pcv-diaphragm-replacement-alternative.1965923/