HI, I have a Q7 3.0 TDI registered Oct 2007 with 225,000kms on the clock. I have been experiencing the following problem with, I think, the turbo. When I start the car and use first thing in the morning the turbo is fine and the car accelerates as normal. I then stop the car (park up for school runs etc) and then when I restart the car the turbo does not work and the car accelerates extremely slowly and going up hill the speed drops out and when going down hill it accelerates up, but still no turbo. When the car is in it's "no turbo" state sometimes after a few kilometres of travelling at at constant speed (100 to 120 kph) the turbo will (without warning) kick back in and suddenly the speed has increased to 140 to 160 kph and just a suddenly can drop out again. Sometimes when it is in turbo mode after a few kilometres of travelling the turbo will drop out. It makes driving the car quite difficult with pulling out at junctions or trying to keep a constant speed going up hills and not causing traffic queues behind me! Without fail the car will have the turbo working fine first thing in the morning every single day! Also the engine management light is on constantly. Audi have said the turbo is on it's way out and needs replacing, but I have always thought that if the turbo goes and needs replacing then that's it, it won't work at all and not come and go as it pleases. Has anyone else had this problem, is it the turbo or is there something else that could be causing the problem such as a sensor? Help!! Thank you :-)