power loss and turbo whine
 

I had high speed (50 mph or >) power loss when accelerating.....it surged or cut out. I replaced the pressure sensor. I now have a whine at turbo spool up. It still surges but its probably less. I rigged a pressure tester and checked for intercooler leaks. Can't find any major leaks just a few small bubbles around one clamp. What could cause turbo whine with high speed power loss. The turbo blades are clean and feel tight...no wobble. Ideas, suggestions appreciated!
Fuel clean, fuel pressure good.

Stock 1999 2 gen 24 valve 5.9 with Fass lift pump.

Nothing here?? It seems to me that mine whines as well, but at 22+ on the gauge. I am trying not go get it that high, dont want to have to buy a turbo right now. Other things first. :tu:

I checked clearance between the turbo blades and housing....it was .015....within specs I believe. No detectable bearing thrust movement. I'm thinking I don't have a failing turbo. Maybe a crack I haven't found yet. I get plenty of leak past through the valves when pressure testing. When the intercooler is blocked on the intake side no leaks detected. Mmmmm what could be making the whine....

even a small leak in the intercooler will result in a neat little whine. consider that at 3000 rpm, your stock engine is pumping around 10,000 cfm. At least that is what the MSHA tag said on mine when I bought it. You can't duplicate that with your little bitty air compressor.

PSI is PSI whether it be air or water at 2 cfm or 100,000 cmf, so if the turbo is moveing 10,000 cfm at @35 psi boost or you turn off the motor and attach a compressor and pressure check the inter cooler at 35 psi it will have the same pressure.