Yesterday pulling my camper my 02 7.3L overheated to the point it said "check gauges". I pulled over and the plastic radiator had pressurized and split on top. The upper radiator hose was very tight so I thought it may be a stuck thermostat. I went and bought a new thermostat and a patch kit to fix the radiator tank. After repairing it I started pulling again and after about 10 miles it heated up again almost to red but then went back down like the thermostat opened up. then about 5 miles further as I was puling a mountain the truck went back into the red again.

The good news was the patch kit held but water was coming out of the radiator cap and the hose was tight again. I let it cool and continued pulling the rest of the way to camp with no more issues. I unhooked and had to go to work this morning and unloaded the truck stayed in the normal temp zone for 60 miles. What could be causing this?

 

Did you hear the fan roaring when it was hot?

 

Did you ever hear your fan kick in? if not your fan clutch could be bad.

 

Well I didn't hear it. When I caranked it back up the fan was turning though. I turned it by hand and it did not turn freely. It had some resistance. How can I check?

 

The fan will turn even when the fan clutch is not engaged. The clutch should engage when underhood temp hits about 220°. It makes a distinctive roaring sound as the blades match the RPMs of the pulley. If you don't hear it than the fan clutch is not functioning properly.

There is an elaborate test in the Ford Service Manual but it requres specific tools and instruments. The best test is do you or don't you hear the fan roar. Unless you have a heavy load in the bed or are towing the fan clutch will not engage. The only time I hear my fan fully engage is pulling a grade while towing. Even then it will engage and disengage, as it should, as the underhood temp rises and falls.

 

Ok I will go get a clutch. Is that a hard install on these trucks?

 

Getting the fan nut loose can be a real PITA.

Here is a video for water pump R&R that has the steps for removing the fan assembly.

Water Pump RnR - YouTube

 

The cluch will not turn freely it will have a very small resistence to it surly the fan is not turning backward, check the fan for conductivity and check the water and antifreeze it should be close to 50/ 50. If this does not work check for the connections on the fan or fans.

 

Welcome to FTE.

These fans are not electric.

 

Sorry, i am confused i guess i need to do a little more research on these before i post a comment.

 

I'm willing to bet the radiator is the issue. Several of us have had similar symptoms to yours. When mine went bad, it would hold temp fine on level ground not under much load but once you started up a hill or put any real load on it, it would overheat. Turned out the radiator was partially clogged and needed to be replaced.

 

When I pulled the fans on the 2 I did, I drained the radiator down to the bottom of the degaus bottle, pulled the top hose loose, pulled the belt off, and then I used a small pair of channel locks that I put on the back side of the water pump pulley gripping it from the top just on the passenger side of center, I held it with one hand, put my 15" crescent wrench on the nut and hit it with a dead blow hammer, it popped loose. Pull the bolts on the degaus bottle and the ones in the top of the fan shroud. turn the degaus bottle so it is out of the way towards the passenger side fender. Then spin the fan off inside the shroud. You should pull the fan and shroud out as one. Replacing the clutch should be straightforward. I had a hard time getting the fan started back on the nut, but a few cuss words later it decided to co-operate. put it all back together in the reverse order. Be careful of how tight you tighten the bolts in the pulley since you can strip them out, or break them off. I think 12 ft lbs is all.

 

I have these come loose often in my vans for some reason...but rarely in the pickups for some reason. Personally, I Loctite them in now and that has been working so far....weird though!

 

you could also have alot of debris between the radiator and the intercooler. Look down between the two. I'll bet it looks like a cats been living in there. this will cause the truck to overheat when you really start to work it. The only way I've ever been able to really get them clean it to pull the rad and pressure wash it while its out. That reminds me, its been about 100K since I did mine. might better pull it and clean it again before I leave Utah this fall.

Barney

 

This happens in our John Deere tractors all the time. We send it to a radiator shop and they "boil" it out. The last radiator we did was 20lb lighter when it came back.

Might also want to check your radiator cap (well the degas bottle cap). If your overflow tank split it sounds like it had more than 16lb in the system.