I know, just picking at him.

 

I think I have a boost control solenoid issue, too. It makes a chirping noise while in boost until it warms up, and then all is well. It's been around for a while.

If I ever get my chassis noises worked out, that's next on my list. 131K miles, so no spring chicken here.

 

The bad solenoid caused an overboost condition, which resulted in a screech. If you're not overboosting, you should look elsewhere for your chirp. Maybe boost leak, low oil pressure, wrong viscosity oil, or, I know you don't want to hear this, your turbo may be on it's way out. Also probably a good idea to try to stay out of boost before the engine is warm.

I'm supposed to be at 14-15 psi boost(stock). The screech I heard was when it hit 23-25 psi(severe overboost).