For the cooling problem, go to the Ford DEALERSHIP and get an ENGINE COOLANT TEMPERATURE sensor. The only reason that I said go to the dealership is because I know that theirs works. I´ve melted 2 others. Fords is metal. If not, also check the fan relay switches, there might be more than one! As for the idle, I´d just go with basic stuff, fuel filter, plugs, super concentrated injector cleaner, etc. I didn´t have probs til I wrecked it. but everythings good now. Good luck with it!!!