My 05 makes a noise on cold morning start ups that sounds like the belt or maybe a pulley or tensioner. I've took it the dealership but of course it will never make the noise then. It does not do it every morning and it usually has to be cold but yesterday it was not cold outside and the truck was not cold either. I had started it up several times running errands and when I started it to head home it was making a constant, very load squaling sound. Imagine the slight chirp the belt will sometimes make when you shut the truck off, times ten. I popped the hood to try and find it but didn't have any luck. I shut the truck off and started it 6 more times and it never done it again and has not done it since. Has anyone else had this problem?