Start up noise
CDomb, I also have a 2002 4.0L that has the same symptoms you described. I was curious if you have figured out what it is. Mine is a chattering noise that I only hear when I accelerate and the rpms are around 3k. Much like yours, the noise will go away as soon as I decelerate. It will only do it when the truck has recently been started and it is still reaching operating temp. Once is has fully warmed up, it will only do it for the first few miles and then it appears to go away completely. Makes you think it is some kind of lubrication problem, but 5/30 is so thin, it doesn't need time to loosen up, so I'm not sure. Also, if you crank it up and let it warm up and then accelerate with it in park, you should notice it doesn't make the noise. Atleast mine doesn't. So maybe something in the tranny?? I've also thought it could be one of the pulleys or accessories, but why would they only make noise when cold? It sucks having a brand new truck that has driveability noise. I'm ready to take it in to the dealer, but you never know what's going to happen there. I did a search and found your thread in hopes that it may be a pervasive problem that Ford may already be aware of. The only other problem I've got is with the ventilation. When I put it on defrost, the air still comes out of the dash vents. Dealer said it is an "air blender" problem and that they would need it for a few days. I shudder to think of them tearing the dash out and then putting it back together halfass. Then you have all those nice little rattles and such. Hope you don't have this problem as well. Anyway, let me know if you've found out anything on the noise!!
