I've got an '03 250 4x4 with a 6.0L 6spd. It's run hot before but it ended up being a hole rubbed in the lower radiator hose and I was losing coolant. I noticed yesterday afternoon a slight burning smell going down the road, but I thought it was the old truck in front of me. Noticed it again this morning, and also noticed my temp guage was bumping on up more than normal. Not all the way, but a good bit warmer. I checked the coolant and it's fine. Plenty of oil and I don't notice any leaks. What else could be causing this? Truck has 85K miles on it and never had any problem besides changing the alternator and that radiator hose.

 

I notice now the temp guage as its warming up is dancing around. Could this be the thermostat? I also heard a strange noise coming from under the hood with the truck off, key on. I comes on and goes off. I traced it to the little solenoid? motor right in front of the blower motor? I think. It's on the passenger side mounted to the fender between the battery and firewall.