Sounds like a bad bearing, Could be alternator, power steering pump, water pump, A/C if you got it. Not likely anything in the motor, behind the CS pulley. Could loosen the belt and insure it's a accessory and not the engine. Then use the hose trick, After hooking the belt back up again.Watch for the fan blades. Stick one end of a rubber hose in your ear. Hold the other end to the Acc's. Help pinpoint where the noise is coming from.