2005 Saturn Vue Whistle and Whining noise

A good suspect when temperature is a factor is a noisy power steering pump. When the noise is occurring, use a stethoscope to listen next to the bearings.

Once the problem is solved you'll need to replace the serpentine belt and scrub all the pulleys with soap and water or an engine degreaser. Serpentine belts must never be coated with any type of lubricant or "mechanic-in-a-can". That will prevent the smooth back side from gripping the pulleys it's going around, and dirt and road dust will stick to it and cause even more squealing. To identify if the belt is causing the noise, when that noise is occurring, dribble a little water on the smooth side. If the noise changes, suspect a pulley that's tipped or turned a little. That will make the belt slide across that pulley as it goes around it. As little as 1/16" misalignment can set up a horrendous squeal.