2005 Ford Focus whining noise in egine compartment

In the mornings or when the car sits for a long time. When driving there is a loud whining noise when accelerating thru the rpm's. The noise is coming from the passenger side of the car up near the engine compartment where the pulleys are located on the duratec 2.3 motor. I have checked the pulleys and the tensioner and they check out okay. Dont know what else would cause this problem but only happens when the engine is cold.