u/Altoid444

I have a 2006 f350 6.0 powerstroke that recently started making a screeching noise coming from the turbo area. It only starts making noise under heavy boost and sometimes doesnt do it at all. It started by doing it every once in a while and now it does it almost everytime I accelerate hard. I also noticed a small but noticeable puddle of oil underneath the driver's side. I know something about the turbo is wrong, but can someone point me to the right direction as to what it is. thanks.