95 deville 4.9L has a whining sound but its not the power steering unit

look for a vacuum leak - that seems to be what you are describing

vacuum leak where the resevoir and part meet? Can i hear it if I was to put a stethiscope on it?

The leak may be there, but hard to say. Your car has quite a few vacuum lines and sometimes it is a challenge to find the leaks. But again - that is what causes the whistling that you are hearing.

Thx

Found it! It's the power steering hose that is n the front drivers side. Leaking where there is a plastic connector and 5/8 in bolt.