Just pull the air intake and see what you have on the turbo for shaft play. A little up and down movement is ok as long is it doesn't touch the housing (that may be what your screeching sound is) but you should have no in/out play in the shaft at all. Also for your screeching sounds does it do it when sitting still as well? May be a serpentine belt idler bearing going bad. If it does it sitting still I would look at the idler pulleys instead of the turbo.