excaliber

My 97 SC400 has recently developed a whining/whirring sound that comes from under the hood at idle. It is loud enough to hear over music and seems to subside when accelerating but at idel, it is loud.
Unrelated or maybe tied to it are 4 episodes of my car having extremely low idle that coincided with the sound resulting in the idle dropping low enough to shut the car down. It did turn back on immediately thereafter.
This happened previously a few years ago and was fixed with a bettery recharge but the sound was not present back then.
I have been noticing a sound when I have had the A/C on before but nothing like this sound which is loud and like the sound you would hear if you were turning wheel while low on power steering fluid. The fluid is good and I dont hear it on turning, just on idle.
Just had inspection done, only faulty part at moment per dealership would be some cracking to my brake lines.

Any ideas, help would be great. One of the things I loved best about my SC is that at idel at stoplights you could barely hear that the car was on and for a 178k mile car thats nice.

Thanks