Turbo Goes Screeeech

[Blatstar]

Hiya.
Have any of you dear folks experienced a high pitched "screech" I presume its turbo related. It happens when the revs reach circa 2700 rpm, disappearing just before 3000rpm whilst accelerating. I was thinking maybe a hose working loose and leaking / screeching or bearings on the way out, cant see anyting loose though and it only seems to make the noise whilst under load, ie there is no sound whilst bringing it through the revs whilst stationary making it a pain to isolate. Any ideas gratefully received? TIA

[allstaruk]

Have you still got the air pump that could well be the cause.

[nikp]

Yeah, could well be the air pump - good call Alan.

[AshRX]

Thats what mine used to do too.

If you havent got the cat anymore, just unplug the wires from the back of the air pump and this will stop it working

[Blatstar]

Thanks for the pointer.
I\'m running a pretty standard car though and, yes the air pump is in place, will give the wire disconnection a go, cheers for the idea.