Seat leon TDI vibrating

[Shwoddy91]

Hi was wondering if anyone could help me, recently purchased a seat Leon 2.0 TDI 06 model, but found that when I acclerate there's is a vibrating noise coming from the engine bay but only upto 2500 revs then it goes. Took it back to the garage and they then took it to 3 different garages and say they can't find the problem, just seeing if anyone else has had this
Thanks