I recently bought a Audi A4 (B7) 2007 S-Line TDI 2.0 170BHP with 73k miles about three months ago from auction, etc. I was driving to work on the M25 for the first time in this car everything has been running fine on it, suddenly I get red flashing oil pressure light, and absolutely no power when I put my foot down. I pulled over initially thinking perhaps its been leaking oil (I saw some on the drive, but not sure if it was my friends old car or mine) topped it up got it slightly over perfect but plenty of oil, started it but once I get over 2000 rev's the "Oil Pressure" light came on, and there was absolutely no power almost as if the turbo wasn't working? None the less it wasn't drivable and I had to arrange recovery. The engine sounds slightly nosier than it should be but it does run, what could this be? Has anyone had this before?