sounds of a turbo dying

It may be an exhaust leak before the turbo. I would check all the bolts in the exhaust manifold. Its my guess that 1 is broke.

 

What year and motor. My accert cat had the same kinda noise and it was 2 things. 1 some of the exhuast sleeves on the manifold where broken and 2 one of the metel pipes had a crack in it from the turbo.

 

when the new turbo was fitted , were the contact surfaces cleaned and a new gasket installed.
P.S u can check for leaks by, spraying soapy water onto surfaces. start tuck run at about 1500RPM for say 3 to 5 mins (or get someone to sit in truck and help) to build boost then with engine still running, spray soapy water onto joins etc.

 

Very interested in the outcome. Yesterday my bxs started making the same noise at 35+ psi.

 

Check the air to air exchanger for cracks with a pressure tester.

 

If you start blowing a LOT of BLACK smoke, shut that truck down or you'll overheat that Turbo, believe me, I've done it.

 

I doubt it's the turbo, I'd say you have an air leak. Inspect the hoses between the turbo aftercooler and engine. You may also have a small crack in the aftercooler. As boost rises it gets worse, because the air pressure is rising and the volume of air escaping through the hole is actually making a noise like a whistle or in this case kazoo