I have a '04 Expedition EB and starting noticing a slight whining noise a few days ago when I accelerated from a full stop or getting up to "in town" speed. I have read several posts on here and majority seem to be around cold weather but that certainly doesn't apply in my case, it's the beginning of August and on average about 90 degrees outside. It sounds similar to a whining power steering pump but when I checked the pump and fluid levels it all looks good. I continued to check all the other fluids(trans, oil, brake) and they all look good too. My family and I went on a bit of a lengthy roadtrip today and it stayed about the same until we were on our way home and I thought I heard a sort of "rattle" when I turned a corner, went several miles and never heard it again until I came up to a stop sign and began to accelerate. That slight rattle I heard earlier suddenly seemed to become a big rattle and the truck didn't seem to accelerate like normal, almost seemed like it had to work a lil harder to get going at first. Once I hit 60 kmph or 40 mph and the transmission shifted the "rattle" seemed to go away but could still hear a bit of a "whine". When we got home I popped the hood and checked all fluids and all were good, started the truck and listened and a similar whining noise seems to be coming from under the plastic cover on top of the motor but I can't say foresure. I'm hoping it's not a transmission issue as we all know they are never cheap fixes. Any suggestions or diagnoses would be greatly appreciated.