I had a lift in a Ford Focus S Max diesel semi auto tonight....with the pending question what do you think in wrong with it.... The noise I can only describe is like taking the tyre inflator of the airline and squeezing the valve to release air. This happens when the car starts to gain revs from stand still. When he dropped me off I watched him 3 point turn and drive off, from the pavement it was quite loud! I thought it might be something to do with the connection between the turbo and the inlet maniford. I don't really know much about the Ford TDCI engines...... suggestions?????? If you were a boy racer I'd say you have a blow of valve?

Boost leak by the sounds of it. That and it's a Ford, so could be all manner of things.