1999 Pont. Bonneville-Replaced upper intake plenum because of crack. Oil changed/radiator fluid changed/belt changed. Ever since repair have been getting a "squealing" sound that comes and goes and is sometimes loud and sometimes quiet. More from under engine. Not in repair area. Tried bypassing A/C compressor. Can't figure out what is cause. There was a lot of leakage/spillover of fluids because of crack and in changing it out. Thought it was antifreeze/fluid on belt but that wasn't it.