Creepy

Ok, few months ago I blew up my engine (Classic 99).
No MAF failure, no nothing, just stupid me driving flatout (and I really mean flatout) with too litlle fuel in the tank = surge = kaboom...

I installed an STI 2.0 semi closed deck enigine, with modified heads and a VF34 turbo, expecting, and getting about 310 Bhp.

All went well, running in (mineral oil for the first 1500 km's, then Castrol RS), mapping, driving...

That was until last week, on my second 'Ring trip^.
After a few laps, I noticed a strange "jet engine" noise coming from the turbo, only on low speeds and rpm's (about 30-40 km/u, below 3000 rpm)

I checked all hoses, clamps, etc but found nothing.
When I blipped the engine, you could hear the turbo making and losing revs, above the engine sound. It was like a jet engine, muted, but still audible.

After another few laps, the sound was still there, but no more or less.
The engine itself performed faultless, making the boost as expected, no overheating ...

Turbo is now of the car, and sended back to the UK for inspection.
(Please don't ask names, won't give them)

What could be wrong ? After just 6000 km of driving ?
Any chance that the bearing is worn out, or the propellor shaft ?
I'm not familiar with the inner side of a turbo, so I expect the company in the UK to have it repaired if necesarry...

Tidgy

could just be a faulty unit, can happen, if the company are being ok about it and say we'll replace it then i wouldn't worry about it.