Hi All

I have a 2011 Passat CC GT TDI 170, it has recently developed a noise. When accelerating hard between 1,500rpm to 2,500rpm there is a loudish suction noise from engine/turbo, abit like air escaping. The car hasn't lost any power, no error lights on dash. Could this be a loose pipe or something more serious as turbo failure?
I plan to remove air box and piping to have a better look, reading many forum posts about turbos, valves in the turbo sticking or pipes split / loose.

Anyone had similar problems?

Thanks