Hi all, I have a 54 plate A3 2.0TDI DSG.. has done 60,000 miles, I had it over a year, have done 10,000 miles in it, all full service history, end of last year, a mis fire started happening, got it diagnosed and it was Number 4 injector - had that replaced, everything was fine up until about 2 months ago.. It started to struggle starting, didnt like turning over.. was putting out ALOT of black smoke which smelt like burning oil/diesel, was running rough like a tractor, gear changes were juddery at around 1400rpm. But then some times it will start fine and drive perfect, then when its turned off and on again it will be rough again.. any ideas to what this could be? I have had this in around 3 local garages and a specialist in Audi and they couldnt diagnose it, took it to a diesel specialist and they couldnt find anything wrong, so I decided to take it to Audi Direct.. Took it in to Poole Audi and all they could tell me was it needs a new Head Cylinder, 4 injectors, Wiring Loom, with a nice bill of just under £6000!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! What was I to think? I have had it parked on my drive ever since seeking different advise from different people and havent got far.. But today some one told me it sounds like a loose ocnnection between wiring loom and the injectors as some times it is fine? They said to try replacing the injector wiring harness? What do you guys think, any advice for me? Much appreciated!