I appreciate this has been done to death already ... but .... Ok, so for the past few weeks I've been stripping down the engine bay - refitting gaskets, shining some things up - but more importantly, going through the entire boost/vac system trying to find this damn leak once and for all. Anyway, I think I found the problem. I took off the crank case breather and the T-piece its connected to - basically its full of coked ****, gunk and the rubber is lame. There is a split in the 90 degree pipe coming from the suction jet pump thing (gaping hole - would never have found it unless I'd removed everything!). So I'm gathering part numbers etc for a phonecall to Audi this week. I have an idea it will cost me a small fortune to replace everything I want. So is there another way (tried and tested ?) of doing this PCV system with silicone hose and pipe fittings ? Surely it would be better in the long run - and replacing any further parts in future would be a hell of a lot easier. Has anyone ever done a DIY PCV ? I need some suggestions (or anywhere to buy cheaper-than-audi OEM parts !). Thanks in advance.