I have a 2001 F350 HD with 7.3L
Temp gauge normally is just below half way
Never hauled heavy load with her before
Air temperature was 104
Total load was 12K lbs
Temp gauge moved to HOT within 30 miles
NO AC engaged
Ran heater fan for extra fluid cooling, limited effect
Pull over and idle, temp would return to normal within 3 minutes
Force turbo to engage while hot the temp would drop
Coasting down hill, temp rises quickly
Installed additional transmissoin cooler on side of road, no change
Maintain slow speed (50 MPH-), temp above normal but not hot
New water pump was installed within the last year
Coolant level normal
Antifreeze % good
Cannot hear fan clutch engage
Radiator is debris free
Transmission was rebuild within 3 months

Need to haul same load cross country and need a resolution.
Replace Fan Clutch? Currently has some resistance when cool. Will drive today and check after hot.
Flush Radiator?

Thank you,

KJ

 

If the fan was cooling, you would hear it. I'm guessing it's not turning. When the fan on my 7.3L is operating there is a very distinct fan howl coming from the front of the engine. With the size of the cooling system on the 7.3L I can't imagine there would be a problem as long as there is good air flow....

 

I think the clutch in your fan might be out. When its 100* out my fan is usually coming on intermittently. And when it comes on you hear it, because first time it comes on you look for the Boeing 707 trying to land next to you. Also, try checking your cooling system for pressure leaks.

 

Welcome to FTE.

I've moved your thread to the 1999 - 2003 7.3L Powerstroke Diesel forum for better assistance.

 

Double post. <filllllllllll>

 

ARGH!! Make that triple post.

 

I had a problem with mine overheating often. Replaced the thermostat quite a few times before I found you should only use a ford thermostat. Installed the ford one, and a new radiator cap, and all is good. Your radiator may be full of weeds, etc, had that happen once.

How loud is the fan clutch when it comes on? I can hear mine, but not very much, not like a semi fan when it comes on.

 

Well, honestly its not the loudest I've heard. That goes to V6 and V8 Tundra/Sequoias from Mid to late 2000s. Those things are LOUD when they start up.

Mine is just loud enough to be heard over the rest of the motor, which isnt quiet either.

 

If you have time then pull the radiator and have it checked for flow restrictions. I had an overheating problem with my F-450 last month and the fins were nice and clean. I took it to a shop anyway just to be sure and they said it was about 25% blocked inside. They cleaned it out and installed some new o-rings on the tanks and it's like a brand new unit. The bill was $95 which wasn't too bad IMO....

Besides, pulling the radiator is much easier than I expected.


Get your engine nice and hot and then watch the fan when you turn off the engine. If it spins 3-4 complete revolutions then you might want to consider replacing the clutch. The fan on two of my trucks stop turning pretty much immediately after the engine shuts off....maybe 2-3 blades past. My '99, which has the original clutch fan and almost 300k miles turns about half a full revolution after the engine shuts off. It still engages well enough when towing a load but I can tell that it doesn't quite 'roar' like my other two trucks do. I think the fan clutches do wear out without completely failing so you may have a partially working fan. You should easily hear the roar of the fan when climbing a hill in second gear. If you are in 3rd or 4th then the roar will be less pronounced.

Good luck. I hope you resolve your issue soon.

 

Here's another 2 cents: one more item to consider is the radiator cap. If it cannot hold pressure it will overheat. Take a look at the gasket in the cap and, if it looks like it will help, flip it over. Otherwise it's not the kind of thing worth testing, simply replace the cap. I saw a thread here where an aftermarket cap was a leaker right off the shelf. For just a few bucks more I'd head to the stealership for a genuine Motorcraft cap.

 

Just did a fan clutch today in one of the E350's...after taking it off, I noticed the large bolt where it secures to the water pump had no resistance left at all. I noticed just by looking at it at idle, was just barely spinning and of course, the A/C wasn't very cold.

Someone REALLY needs to make a tool for the van's....getting the fan clutch off w/ the regular 7.3 SuperDuty set just sucks!!!! The van's need an offset wrench!

 

I drove the truck this afternoon with the air temp at 101. I also kept it out of overdrive to increase RPMs. When I turned the truck off the fan stoped within 1/3 of a revolution. The resistance to spin the fan by hand was the same hot as when it was cold. I am still not sure that the fan is really locking in as I cannot hear it. The fan spins the entire time, from cold to hot. The radiator cap (if want to call it that) is on the overflow reservour and had pressure when I unscrewed it 2 hours after it was parked.

Welcome your thoughts on replacing the clutch as well as removing the radiator to have it checked/flushed? Any other thoughts would be welcome as well.

KJ

 

Yes, lots of guys on here have overheated, changed everything and it ended up being the radiator. Your cap sounds good. Fan seems good but I would pull the radiator, have it roded out and checked. You could go buy a new one but if you have a shop close by I'd have it gone threw. You already changed the water pump last year and if it ain't leaken it probably good. You r stat could be bad but not to many problems with stock stat's. Let us know,

Chet

 

when it is warmed up turn it off and feel the radiator core with your hand on the fan side if the middle feels colder than the rest it will be blocked and will also stop the fan from working as the clutch will not get to working temp because the part of the radiator in front of it has no flow inturn not warming up.
i had the same problem a few months back it would only heat up towing up a hill, when i removed the top tank i found approx 8 tubes flowing under the top fitting and 8 or so on the far side the middle was completly blocked. a good rod out of every tube and pressure flush shes 100% again..

 

Currently doing a heavy load and can't be sure if the turbo is the problem but the fan that comes on when in overdrive going up hills is coming on at rpm 3000 to 2500 and wants to overheat. Only backing off speed brings the temp back down but am not able to run at 55mph or so. I am reading above that there may be a related Rad Fan problem or should consider checking in order to correct this potential problem?? Any clarification would be appreciated. Have changed the fuel filter this morning. Would also changing the air filter help? Thanks!