While taking a long trip, I started getting a whistling, /screeching sound during heavy throttle. I was afraid it was my tranny as it leaks like a sieve, but then noticed muy boost gauge reading a few psi lower than normal. So I figured I had a small hole in a tube. When I got home and looked at everything, I found one of the bolts that holds the compressor scroll on was gone and there was close to a 1/8" gap between the scroll and back plate. The o-ring looks like it was getting blown out the gap, the source of my noise. Most of the other bolds had been pressed into the aluminum of the back plate by the force, so I had to steal one bolt off the VNT Libbybapa sent me, and put larger washers on it and the others as I didn't trust the small contact area any more. Hopefully the compressor and scroll didn't get damaged, but everything seems like it was.
So if you notice lower boost and hear a funny screech, better check those turbo bolts!
thats pretty scary! what about any preventative measures like using thread locker on the bolts??? blue should suffice? or red?
I haven't yet as it is hard to get to them, and even harder to get the turbo out. I'll just keep an eye on them.