Overheating 7.3L diesel

[sac1ses]

I have a 2002 F350 SD crew cab 4X4 with approx 210,000 miles on it and it is overheating when I pull my 5th wheel or my boat. I'm running 285 tires with 3:73 gears and the truck is all stock except for a K&N air filter. The boats weighs in about 4K and the 5th wheel weighs in about 13,000K. When I pull any type of grade the temp gauge rises to the red. When it gets to that point I pull over and rev the motor up to about 1500 to 1800 rpm's and it cools right down. I have replaced the fan clutch with a Ford factory unit, the radiator and cap, the water pump & thermostat but the problem still exists. When the engine starts to overheat the fan clutch doesn't come on until I pull over and after the motor cools down it will stay on for awhile once I start going again but eventually goes off again. I'm totally confused as to why the fan clutch doesn't come on when the temp rises. I would think that it would. Any suggestions are appreciated !!!

 

[JRJ04]

are you sure its actually overheating? maybe its just a bad sending unit?

 

[sac1ses]

No I'm not sure its the sending unit. But I would think that if it is a sending unit it would register overheating pulling a load or not, wouldn't it?

 

[dpantazis]

the gauge on the dash is nothing more than an idiot light. you want a real thermometer to read temps.
second, get rid of the k&n crap, it will ruin your motor. go low buck and do the diy filter in the wiki.

 

[Tbar]

As this is your first post to SDD.........Welcome!!!

It is a little unusual for a 7.3 engine to over heat. Is it blowing coolant.......do you smell it? What is the level in your reservoir tank?


Tbar

 

[sac1ses]

No coolant is being lost and it doesn't smell like it is overheating. The resevoir is at the right level.

 

[JRJ04]

the gauge on the dash is nothing more than an idiot light. you want a real thermometer to read temps.
second, get rid of the k&n crap, it will ruin your motor. go low buck and do the diy filter in the wiki.

x2 on the k&n removal. the drop in filters were the absolute worst kind you could put in your truck.

the DIY is almost as good as the afe stage II with the pg7 filter.

 

[Tail_Gunner]

What ever you do-----
DON'T GET YOUR TEMP SENSOR FROM ANYBODY BUT FORD!!!

I have a little bit of experience in the area.
READ HERE.

 

[LonestarBronco]

second, get rid of the k&n crap, it will ruin your motor.

Do tell...

 

[DaveBen]

K&N filters don't filter very well. They will let dust and the like through the filter and this will damage your turbo intake blades. It can destroy a turbo in no time. How long?? I don't know, I have never hurt my turbocharger.

Dave