Hi, this is my first post and I'm hoping someone can help. I have a 2001 A4 130 Sport which has developed a droning noise. I thought it wa the exhause, but I had it checked by my local dealer and they said it was fine; they suggested the air filter, which I changed but the noise is still there so I'm back to square one. The noise sounds like its coming from the drivers side of the engine bay (around the air box / turbo pipes) does anyone have any ideas??