Squealing noise only when I pull off, what is it?

The loud screeching you're hearing is the serpentine belt under the hood. Or you might have a vee belt. Check adjustment of the vee belt. And if a serpentine belt, the tensioner may need replacement. Take it to a shop that you trust. I've had 2 vehicles that has squealing serpentine belts. It's not that big of a deal; just doesn't sound too good. Also you may have a small coolant leak getting on the belt and causing the squealing. There's spray stuff called belt dressing. Once a month or so applications may cure it.