Originally Posted by Goran (Post 86909)

I think I found it, should be fuse S130, a 50A fuse. I cant work out where its supposed to be in the drivers footwell on the side, or in one of the other fuse boxes. Maybe I'm being thick I cant find a fuse diagram in ElsaWin, surely there should be one?
Relay should be no. 4 in the passaenger footwell?

http://forum.a8parts.co.uk/attachmen...1&d=1420394804

Originally Posted by Goran (Post 86754)

I think you're onto something there! perhaps the rubber diaphragm has failed and is vibrating as it lets air out?

Its the black plastic UFO type object at the back of the engine.

Here it is in a picture I borrowed from another forum member's post as it shows the engine bay without covers.

It is easy to remove by jubilee clip or the Audi type clip, but I'm not sure if its safe to run the engine without it or with the rubber hose plugged to test if the noise stops?
Probably ok for a minute or two, as its just a sprung rubber diaphragm to let some crankcase pressure out when it builds up enough to be able to open the diaphragm.

This is how it looks inside:

http://forums.quattroworld.com/a8/threads/8649.phtml

http://forum.a8parts.co.uk/attachmen...1&d=1420113692

Originally Posted by mark_le_b (Post 87239)

Eureka! This is the problem, found this was the noise this afternoon
Can anybody help with a part number so I can order a new one
I assume its easy enough to change over
Thanks

Originally Posted by steamship (Post 87242)

The part number is 077103245B. As for fitting, it is held in place by two clips. I had mine replaced a little while back and just used bog standard Jubilee clips instead of the OEM type used by Audi.

Originally Posted by Adrian E (Post 87245)

Same component failed on our A6 Avant 3.0 petrol - sounded horrific but noise went away off idle. On stripping it the valve was full of crud, so be prepared to spend some time removing pipes in the vicinity and checking they're not blocked and/or squidgy from oil.

Not sure if it's the same for the '8 as was the case for the A6 but there were 2 part numbers, one being for a kit which included more bits and wasn't much different on price but included a couple of pipes - worth querying when you order +++

Originally Posted by HPsauce (Post 87251)

It's worth just taking it off (dead easy with the right clic-r tool) and taking it apart (very simple) and checking/cleaning it.

Mine had a tiny tear in the very edge of the diaphragm which I reckoned wasn't a problem (probably clamped between the two halves of the body) but I bought a new one eventually just in case.

Once it's cleaned it's very easy to test it works by sucking and blowing into the appropriate orifice!

Kept my old one anyway as "backup". Part number on the casing is 077 103 245 B.