So I have a 2006 f350 6.0
I am having some overheating issues and I am stumped now, it is studded and deleted.
Anyways, everytime I'm going uphill it overheats, I have done the clutch fan, water pump and thermostat.
I'm at a loss for whatever the issue may be.

 

possible leak where upper hose meets radiator?

Have your cooling system professionally pressure tested.

 

When was the last time it was flushed with VC-9? Oil cooler replaced? Any scan tool such as FORScan so you can post numbers? Have you checked out the stickies in the 6.0 section of the forum?

 

So first, what are you calling overheating? Is the temperature just climbing to a higher temp for a bit, and then cools back off, or is it actually overheating and not cooling back off? If it's just raising a bit then cooling back off when the load comes off the truck, you might be making a mountain out of a mole hill, though it's still a good idea to look into it in case something is going on.

There are several things you can try to do. You can have the system pressure tested (not a bad idea) to make sure you don't have a leak, though you're not talking about adding coolant all the time so I doubt you do.

Check the level of the Ford additive that you need to add to the coolant system. If that is low you'll have some cooling issues. If you didn't add it when you did the water pump and thermostat then you need to add it.

While you're at it, make sure you got the mix right, if it's off then the coolant can't collect and disperse heat the way it's supposed to.

If the coolant checks out, then get an infrared thermometer and get your truck good and hot, then check the temperature difference between your upper radiator hose and your lower hose. I forget what the difference should be but there should be one. This lets you know if you're getting good cooling. Also check your radiator with it - if your radiator is partially clogged, the top will be hot and the bottom will be considerably cooler, maybe even ambient if it's REALLY bad. If you've got this issue, I recommend just replacing it just based on the age; if it's original then it's 18 years old, and trying to flush it out or tear it down and clean it could open you up to leaks you didn't have before.

One other thing to look at is your delta between your oil temp and coolant temp - oil should be LESS than 10 degrees hotter than the coolant. If the delta is more than that you need to either have your oil cooler flushed OR replaced, if you replace it get the relocation kit that moves it out of the engine valley.