07 f150 overheating problems! any suggestions

i have an 07 crewcab f150 with 90,000 miles. when it sits and idles for more than 5 min the air conditioning turns to hot air and then as i take off to leave the temp gauge goes from in the middle of the gauge to the full overheating piont within a blink of an eye. and the chek gauges light comes on. If i pull over and shut the truck off and relieve the air out of the overflow bottle which can take up to 10 min then start back up and take off it is fine again untill i let it sit and idle for a bit again. I just changed thermostat and did a full tune up but it was still doing this before i did tune up. any suggetions? It only doe this at idle. If i am on the move driving i have no problems even when pulling my 24 ft camper. not sure where to start.

I would check and makes sure that the cooling system is full of coolant and no air pockets exist. That is my only suggestion thus far. Check your manual or under the hood to see if there are filling instructions for the cooling system.

Are your coolkant fans working properly, are they on when the ac is turned on??

Just wondering if you figured this problem out? We are having the exact same issues with our 07 f150 5.4L truck. Took it to the dealership and they couldn't find anything but $2000.00 worth of work they said needs to be done to the power steering... and we only have 43,000 miles on it!

try flushing and changing thermostat power steering has nothing to do with over heatings power steering just makes it hard to turn when it goes out FLUSH AND OR REPLACE RADIATOR as well as thermostat also check your water pump your water pump could be broken one way to check your power steering is wake up in mornin start it up and then take off the radiator cap when your water pump is running fluid should ever be going down or up if your fluid just sits there you have a clog or the problems i listed going on

Thanks for the reply. We did know that the power steering had nothing to do with the overheating... just meant that the dealer couldn't find anything wrong that would cause it to heat and they did check what you mentioned! We just traded it in on a 2010 - figured if Ford mechanics couldn't figure it out then we weren't keeping as that has the potential to be an expensive fix if it burns out the motor. Not our problem now and the 2010 is working wonderful so far. Plus we love the new transmission for pulling.