Mine fan clutch was doing the same thing on my 2006 F350. There is a connection on the fan shroud that can loosen over time and cause the fan not to work. I did end up replacing my fan clutch in Janurary and just had to replace my oil and egr coolers. Also swapped out the Ford Gold******for some new Cat ElC anti freeze along with radiator cap. Cooling like a champ now and it should, stupid thing cost me nearly $2500. Can't wait to pull the fiver in two weeks and not worry about cooling issues. Gotta love the 6.0. Travel on.
