Um.... well.... I guess that all those Ford Diesels headed to Flagstaff today that were passing me hauling triple axle toy haulers up a 6% grade in 112 temps were overheated? People tow 15K up 6% grades every day here in AZ in temps that sometimes get near 119 degrees and do not overheat. I have never even come close to overheating while towing my 11k hauler, nor have I even had to get out of the throttle due to EGT's being to high. My truck is straight piped an on stock tuning. I usually run 55-70 mph up 6% grades as long as no one slower pulls in front of me and slows me down. I don't believe you statement above is correct or maybe you were meaning something else?

 

All I can tell you is what my experience has been .... with an 11k load (8k for the truck, 11k load, 2-4k for the trailer = 23k all up) going up a 6% grade (Laughlin - coming and going to Flagstaff) if you don't back off you will overheat. EGT's don't come into the equation because at 2,000 RPM plus they will be around 1,000 degree's but your fluid temps will be at or above the defuel limits. I know this to be factually correct. It's also been verified by others, several 6.0 and 1 x 6.4 who actually overheated and had to pull over. The guys you refer to are either lighter or blissfully unaware of how hot their trucks are getting. They may also be tuned which may or may not have a large impact on their opertating temps..

I also took the original post as asking about replacing the engine fan or making it almost redundant so that it did not come on (thereby not making any sound).

A/C temps - I havent noticed much (if any) difference in stop and go and highway, but I can only tell you what my truck does. If you have an 8 deg difference then thats what you have. You also have much higher inside ambient temps too though.

Anyways, like I said, thats been my observations. If you fit them and they work then thats excellent. What I would like to know is if it actually reduces the fan engagement time or lock up amount?

Cheers.

 

That's a 15k load, not a 11k load. The trailer counts too.

 

I appreciate all the advice; I am not totally convinced that the noise is coming from the fan blades. I am used to the roar of the blades; the noise I am trying to describe is different than that. The service manager at the ford truck shop said that it is belt slipping noise caused by the excessive heat in the engine compartment. He told me that I should use either wd-40 to clean up and lube the belt or belt dressing to the same end. I was thinking that if I put electric fans on then that would remove the belt slipping noise all together because there would be no belt on the fan at all. That of course would not fix the problem if the belt is slipping on a different accessory or pully. My other though was to some how create airflow around the engine by putting a scooped hood or some other inlet on the engine compartment to get the temps around the engine block down. Any ideas...?

 

What would you say would be a heavy load

 

11k is getting there I guess, I'd say 15k is heavy. Grossing 31.5k was REALLY heavy, but still didn't have any problems and pulling up a 7% grade wasn't bad.