Re-read your post. Bad turbo. Unless you left something out. In my history, I swore a John Deere turbo felt and spun free, Lost my shirt on that...
That is not Heavy Brass Tarnish and Corrosion, Think of it as Patina. Some folk pay extra for that. Brush on some On-Off gell and hos it off in...
Bad turbo. Bad turbo. Bad turbo. Bad air filter or air restriction??? Naw, Bad turbo.
Just looking at those canal walls, You know something is going to slide off. Just don't know when...