KendallH

So when I first swapped my rb, and had the intercooler piping fabbed and everything, when the motor was revved the turbo would make a noise similar to a KB cobra (supercharger). High pitch whirr/whine kind of noise. The few times I drove it like this it was a constant sound when applying throttle. Figured the turbo was bad so replaced it with a larger T3. Now I'm looking to go back to a stock setup but I can't shake the idea that the turbo was actually good. I was looking at the old one the other day and the wastegate actuator was missing the clip and completely off the wastegate flapper. Reading up online I read a few articles that said that may have been the cause of the sound. It also built no boost while driving (duh). While there was a small amount of oil in the outlet elbow, there is very little side-side shaftplay, and no in-out. So my question would be, could the old turbo actually be ok?

waste_of_space

I had one of my turbo's start making a supercharger-like noise, and it was actually the compressor blade eating the inside of the compressor housing.
Check your turbo for up and down shaft play, and try and inspect the tops of the blades if you can.