"93 Subaru legacy 175,000 miles: Just picked it up yesterday after timing belt/water pump replacement. Now it makes a high pitched whining noise sounds like from engine, the mechanic called it a whistle, but it ain’t no whistle and wasn’t there before.
Were all of the belt tensioners replaced?
Take it back. It could be the belt wasn’t tensioned properly. Did they replace the tensioner with the timing belt. Could be new water pump bearing. Or it could be new serpentine belt or tensioner.
A whine can also be caused by an excessively tight belt and which will mimic a failing tensioner bearing.