Over the summer I took a long trip with my loaded up travel trailer and the bed full of gear. I'm guessing the TT weighed 6k loaded. In the truck bed I had 55Gal of water, 25Gal of Gas, and 5Gal of diesel and a small generator. Then we piled in a bunch of camping gear, geodesic dome, big coolers, etc. I don't know what I weighed in total, but I'm guessing 14-15k+.

So there was one long grade on I-5 South, North of Medford where things got a bit warm. I shifted down to 4th and kept my RPMS at about 2700. I was prolly doing 50MPH or so. My speedo doesn't work so I'm not sure. My EGTs held steady at about 1100. It took at least 10-15 minutes to climb this grade and during that time I watched my water temp slowly climb almost to the red. It never actually got to the red, but it was just shy of the upper "normal" range mark.

So my question is: is this normal behavior? I can see how sustaining 1100 EGT for 15 minutes would put a lot of heat into the cooling system. Is this a sign that something is wrong?

Please see my sig for truck info.

 

Sounds normal to me. I can get mine up to warm side of the gauge climbing rt.66 up into Estes park on a hot day at a good clip with just 500 pounds in the bed. That's about a 10 minute give-or-take pass up through some pretty steep grades.

I don't think the radiators on these things are near big enough.

 

Sounds normal to me. I wouldn't think anything is wrong with your truck. If it happens unloaded, on flat ground, then you might have a problem...

 

If the temp spikes when you floor it on flat ground with no load, it's a good sign your head gasket is toast. . . ask me how I know.

 

 

I towed with a 89 I used to have. About 9 k behind the 6 k truck. On long hills she would creep up. Also used to plow with that one and with heavy wet snow and long camp roads the temp would rise up to where I had to keep an eye on things. The later may have been due to a weak fan clutch.

 

Non i/c trucks had a crappier rad in them factory then the intercooled trucks. the Intercooled trucks also had a better water pump factory.

 

Mine does the same thing, and is gradually getting worst. It started with me noticing when I first cranked I could see the rise and fall of the temp gauge at idle as what I suspect is the thermostat opening and closing. I then changed to the Cummins thermostat thinking that would help and it did not cure that problem. Now even on flat ground its runs right in the middle of the gauge and if I go up a hill or mash it to pass it rises over a little past Wannadiesel's high operating range mark.

How do I diagnose the headgasket? Come to think of it it might make sense as I am battling a boost issue that I thought was part of the wastegate on a used 12 housing I bought. Maybe my issue has been the headgasket all along.....

Sorry for the hi-jack!

 

The first time my head gasket went, it would lift under boost. That was when I would see a spike in coolant temp when I mashed on the throttle unloaded. The cylinder pressure was bleeding off into the cooling system and pushing coolant out and overflowing my overflow bottle.
The second time my head gasket went, I had put a cheap thermostat in my truck and it decided not to open, which led to my truck over heating badly.(I guess I needed to watch my gauges better) After the truck over heated I found pieces of my head gasket in the radiator. It also started blowing coolant out between the block and the head.
Both times the head gasket blew I found black soot, or carbon looking material in the radiator. Another thing to look for is oil in the water or water in the oil.
By the way, both head gaskets let go just under a month apart. Don't buy a cheap thermostat, and make sure to check your gauges.

 

When I installed my h2o temp gauge I realized that 'normal operating range' on the stock gauge was over 200deg

 

I bet the "H" on the gauge means about 240 or so.

 

Wow but my question is this . I have installed autometer gauges in my truck and when that baby hits 180 my stat opens up then i wait till 190 and i throw my electric fans on. Is this the right thing to do?

 

Sure, 190 is plenty warm. 220 is as about as hot as I'd want it to ever get, but there's nothing wrong with running around all day at 210.