Recond, turbo fitted now noisey at high revs!

Right last week i pulled in a favour and got my spare turbo reconditioned.

So last night went to fit it. First problem was the pipes either side were far from a snug fit, hence some exhaust gasket was required.

But today whilst running her out on the A1 (M) i noticed that at high revs the turbo is noisey but not in a whistling way! Sounds more like the blades spinning roughly.

I primed the turbo whilst fitting and she aint smoking or losing oil, so do these turbos have a beding in period or have i got a poor recond,d turbo?

i,m rambling but was up all night on duty and wrestling wea ma wagon!

Right removed my down pipe de cat the day and ran the engine and there was no screech/whistle.

So i fitted a new down pipe with cat genuine part and took her fur a drive and the noise returned!

So in ma crazy head this suggests to much back pressure and the screech may infact be air escaping. On friday i,ll split the exhaust (again ) and take her fur a spin to see if this cures the noise...

My other idea is the turbo pressure to fuel pump line, it dont feel to solid where it fits to the turbo.......i,ll swap it fur a good one from a works vehicle and try that................the joys of 300tdi,s!