Helllo! Just bought a 2.0 tdi 2003 A3, and obviously tried finding out the power of it, i basiclaly tried going as fast as i could on the motorway and, in 5th doing 80mph and the car totally tops out and slows down to around 50-60!

This has put a downer on my purchase!

does anyone know why it does this?!?!? it seems to lose the turbo as well when in lower gears, however this restores when turning the engine off then restarting it, but tops out at 80 again!

any help would be appreciated thanks!!!