At idle (and even during acceleration) there is loud grinding noise coming from under the hood. At first I thought the bearings in the alternator were shot or on their way out but the alt is charging fine and after putting on a different alternator the grinding was still there. I thought power steering pump but turning it by hand didnt produce any grinding and running the a/c also made no difference.
It's not heat shield grind, it def. sounds more like a bearing on something going out grinding.