I have been dying to know what this whistling/squealing noise coming from under the hood of my pathfinder is. I can't pin-point exactly where the noise is coming from, but it seems to be coming from around the area where the fan/fanbelts are located. The quality of the video distorts the sound a little bit, but you'll get the general idea of what it sounds like.
I have noticed that the noise is non-existant until the engine warms up. For example, on cold winter mornings there is no noise...at least not until the car starts warming up.
I don't know if this will help, but I have a 2000 Nissan Pathfinder LE with 113,247 miles on it. Thanks