Could be CAM phasers. Best way to test it is to get up next to a building with your window down, like when you are waiting at a drive thru. If you hear a loud ticking echoing off the wall, it would probably be a CAM phaser.
On the other hand, it could be the lifters. The lifters are notoriously loud on this truck, so it would not be a surprise if that is the source. Maybe the cold weather restricts oil from reaching the lifters somehow? Anyways, I've read that changing the oil may help, but do NOT use a Fram filter.
Lastly, if it is a whine, it is probably an idler pulley, which is an easy fix. Let us know what you find out!
Last edited by Walkerrun; Today at 01:24 AM.