This sounds like the power steering pump. If you only took off the serpentine belt there is one more belt that drives the power steering pump. The pump is on the back side of the engine on top. My 02 stratus had this whine issue and while everything worked well, it also made a whiring and grinding noise and then i knew it was time to replace that. Took care of most of the noise when i did. Just a thought to maybe check that and pull that belt off too. The interesting thing is i had trouble with all the accessories on that car, all made grinding noises, ac compressor, alternator and then the power steering pump. Amazing how much noise and vibration each can make when they are ready to go out.