don’t think I overheated because I made it up here to North Carolina with Towing my son’s car on with my 92 F250

but I was constantly seeing temperatures around 200 driving up with AC on max hauling my sons car. It was an extremely hot day max temp I saw on my gauge was 210°. This was when we were idling at a rest area for about 40 minutes with the a/c on. on the interstate doing about 60 I saw about 200 maybe 195

 

If you have a 195F thermostat, it starts to open at that... not fully open.

I would not be concerned with those temps pulling, in summer, with AC blowing.

 

If your temp rises when you're at a stop, that means your fan isnt pulling enough air. Is your fan shroud in place? Some folks remove this plastic shroud because it's difficult to get in and out, but it's a vital part of the cooling system. Gaps around the fan shroud will cause it to suck air around the radiator, instead of through it.
Your fan clutch may be getting weak too. You should hear it lock up and it'll sound like a hair dryer turning on under your hood while you're on the high way. If you've never heard your fan clutch lock up, it's probably getting weak and should be replaced.

 

when I get home, new radiator and new fan clutch coming.

tranny was fine. 90 % of the trip @ 160 degrees and idling for a period of time one 180

 

If your radiator isnt leaking, I wouldn't replace it. Low engine temps at highway speeds means your radiator is cooling properly, even at high power setting.
Find a good long hill to climb at full power at above 65mph and see what your temps do. If the engine stays cool, then you have a great radiator. Don't replace good parts with questionable new parts.

 

OK, makes good sense. Though it is the original radiator with 76000 original miles

what engine temps do the 5.8 run at ? `and what’s not good

 

don't matter much what engine, if the water starts to boil and it leaves, that is too hot.

200-225 is pretty much normal on hot days.

IIRC, the cap on my 7.3L states 15 psi.

some cars have 17 psi or higher.

 

X2
I have pulled many a trailers, 1 and 2 car, in summer heat.
Because you are working the motor more with the load it will run a little hotter and more so pulling step long hills.

As for the temp going up at the rest area with AC on my 81 F100 with a 300 six dose the same thing and I dont worry about it because once I get going again it comes right back down.

Someone pointed out the radiator caps show pressure on them.
Know for every 1 psi it raises the system the boiling point up 2*f
So if water boils at 212*f and add a 12 psi cap the water will not boil till it gets to 236*f
Add anti freeze / anti boil and it will be a little higher.
With that I would not worry till the temp go to 230*f to 240*f and if I am almost to the top of the hill I would keep going as it will cool off going down the other side.

If you are that worried turn off the trucks AC, less load on motor and no heat from condenser heating the radiator, and do the old 260 AC (roll down 2 windows and do 60 mph) and turn on the heat.
The small radiator, heater core, will pull out a lot of heat when needed.

I would not worry with what you are showing for temp.
BTW if you had a temp light it would not of been on and you would of never known the temp went up a little.
Dave ----

 

I would put a new possibly bigger aluminum radiator in it

 

having put in last week, auto meter gauges it makes you feel a lot more confident on what the truck is doing. I like I said in a previous post up above that the temp was hovering around 195 200 for the majority of the trip pretty stable.

it’s nice having actual gauges

 

Paul that’s what I’m thinking of doing

 

It's a running discussion as some like the factory gauges and others say they are junk and run after market.
Yes factory dose not give numbers but if it runs in the center of the gauge that is normal.
If it goes higher or lower and stays there then look into it and test with an after market gauge.
Me I dont have a issue with the factory gauges for everyday use.

I dont see the need if the temp with after market gauge is staying with in the range of the stat.
If you spend all that money for a larger alum radiator and it still runs in the 195 - 200 range then what?

BTW I drive a big rig and when loaded and pulling a long hill the temp will go up and at about the 200* the fan locks (air lock like a clutch fan) and the temp will come down. I have also seen this on my own trucks when pulling long hills, temp will go up till you start down the other side.
Again this is normal when a motor is working hard pulling a load up a hill.

If the temp DID NOT come down then I may look into replacing the radiator.
Dave ----

 

Dave I am checking with my repair shop to see what T stat they put in and I’m sure it’s 195. If this is the case then I have reconsidered and I’m gonna keep the radiator that I have. I made it back from North Carolina with no trailer just a truck and the temps were pretty much in the same range.