I have had a similar problem with sudden lack of power going up steady hills. Need to change to 4th and can only manage 60mph. First happened on MI heading north past Lakes in June 2010. Fine when we levelled out and for remainder of long journey to Aberdeen and Chichester. Did not happen again for almost a year. Now happening more often but still unpredictable – always the same and you can feel the power drain away, 60mph in 4th is all it can manage uphill. I have owned 1.4 TDi 90bhp since new. All services by Audi until last time when I went to cheap local guy – service was fine, but he wasn't keen to investigate the power drain. Reading this blog, I guess it may be a split/loose turbo boost signal line, leaking intercooler or something called a MAF sensor, or maybe those turbo vanes? What I don't understand is why it happens intermittently rather than all the time. Useful suggestions that avoid wasting lots of money at a garage anywhere near Portsmouth or Chichester (any recommendations?) would be helpful. Otherwise, it's a great car!