OK, first the good news. The old truck made it to Phoenix and back. (I'm in KC, Missouri) Now the bad...

I know that these trucks run hot. (Mine is a F150 4x4 with a 351m and an automatic...c6 I think) Truck spends most of its drive time with the temp gauge on the "m" or "a" of "normal".

Several times yesterday, the truck got WAY too hot while trying to drive the freeway. We had a load, but not ridiculous. (A teenyboppers entire worldly possessions=16 garbage bags full of clothes...) It was warm outside...100 degrees or so. Truck would run fine for 10 or 15 minutes, then overheat. I'd pull off at an exit and let the truck cool down and do it again. For eight hours. Once, the sun went down, the truck was still running warm, but not overheating and we drove straight through the night.

When hot, the upper radiator hose wasn't hard. I think it should have been. We were not losing water or oil or having any other issues. Just getting too hot.

Anything I can do? Or just keep this truck out of the desert in August...

 

are you sure coolant is circulating? Does it have a fan shroud? have you had the truck long?

 

What made you think it was running Too Hot/Overheat ?

Did the gauge go past H

What is blowing out coolant ?

I don't think it did because you would have mentioned that.

Unless it blows coolant the engine was running within its parameters >

 

Yes, I believe the coolant is circulating. With the cap off, you can observe the rise and fall, thus flow. Yes, it does have a fan shroud. I've had the truck since April.

Dennis, as you know, I've got several other issues with this truck. I didn't want to blow a head or head gasket. Normally, I can keep the trucks temp around the a or l in the word normal. Several times yesterday, the needle went past the word normal, and past the little graphic mark, but not past H. I didn't want to push my luck.

No, I never lost any coolant. You thinking I was fine and a little paranoid? Could be...

 

My 77 F 600 had started to run a little hotter than normal too. I found the problem in the radiator. It was partially clogged. I had a radiator from my 79 F 250 that I had parted out a couple of years ago and it was the Super Cooler rad. so I put it in my F-600. It fit like it was made for it. Yesterday it was over a hundred degrees here and I made a 260 mile round trip to Houston and back to pick up an F 600 that a friend had given me. I loaded the truck on the back which was a hell of a load for the 600, and came on back home with absolutely no heating problems at all. I will post a picture of the 77 in my gallery so you can see the beast I was hauling. Also I might add that when I was using the 250 that the rad. came out of, I was towing a 32 foot travel trailer and I towed that trailer all over the Southwest and the Rockies and never had a heating problem. The Ford Super Cooler radiator may be worth looking into after you have checked all the other possibilities for your over heating problem.

Michelle

 

The gauge should not be "normally" there. The reasons the gauge is reading up by the "a"is, you have a higher than normal t-stat, the gauge is off, the sending unit is off, or you have cooling issues.

The problem you describe leads me to think you either have abmormally low coolant flow (anywhere in the system), a weak radiator cap, a lean condition in your carb/intake system, or your timing is too retarded.

 

Thanks for all of the advice. As this truck just became my daily driver, I'll get into it tommorow. I'm thinking that the thermostat is either the wrong one, or malfunctioning. It got us home, and got me to work today. I've only got a ten or eleven mile drive to work, and the truck did fine this morning. I'll be changing oil and checking that tstat tommorow.

 

The thermostat is basically only a switch.

It opens at a certain temperature and STAYS open as long as the temperature remain above that designated opening temp.

The Thermostat is not the problem,

Ford gauges are "NOT the Gospel Truth" to believe they read exactly what the temperature of the coolant is a false hope.

IMO there isn't anything wrong with that truck that a cooler climate wouldn't solve.

Because the system circuitry is built on an electrical pulse and a internal Sending Unit "ground out" there are way too many chances of a "little quiver" happening.

If there isn't any "gushing out of coolant" via the rad cap the temp of the coolant is within normal operating temps.

 

Yeah, I kind of got that idea. The truck lives in Missouri and won't see the desert again anytime soon. I'm hoping to do a rebuild in the spring. (engine rebuild, not the whole truck...) Lots of small issues that I hope to eliminate in the process.

Thanks for the input.

 

Got a question about my new cast iron "Flow Kooler" "12-fin impeller" water pump from Summit...

Anybody else ever try one?

Mine had to be modified. :/ It had a 3/8" pin where a 3/8" threaded hole should be. Also the height of the "boss" was lower by about 9/16". So I threaded the 3/8" hole with 7/16-14 and glued in a grade 8 stud and an extra thick 7/16" nut in place with LocTite 609 and drilled out the accessory parts that go over that stud.

It seems it does run cooler, but hadn't had it going much since the swap due to other things I'm working on.

One thing that turned out good is the belts line up "perfect" without shims etc like the last water pump needed.

Also anybody else use a piece of 5/8" inside diameter A/C hose for the bypass hose?

Oh yeah... and Permatex has some new (new only to me?) "coolant resistant" RTV that's guaranteed not to leak.

Alvin in AZ

 

after dealing with my 460 running hot on the highway for a couple years, i researched this site and several others on the issue...what ive come to find out about highway driving overheating is, that it usually comes down to flow problems (like a clogged radiator or the block's water jackets), or the system not holding pressure (faulty radiator cap, or a pinhole leak in the system somewhere) when a water pump goes bad, it either leaks from bad seals, or makes noise from the impeller being broke off...my motor turned out to have the back half of the block's water jackets clogged with radiator stopleak i found that out after pulling the heads.....

im thinking about doing a overheating experiment with my truck sometime....i plan to remove the shroud and fan (replacing the pully bolts of course) and then drive on the highway to see what the temp does...id bet money that it runs at 210 like normal, until i slow down to stop...i want to do this to prove the old arguement about highway overheating being due to a bad fan clutch or missing shroud....yeah, fan shrouds, thats another old arguement, some say they are required for low speed cooling, but my friends 460 in his F-250 never overheats and hasnt had a fan shroud since he bought it...ok im done rambling, it friday and im getting carried away...

 

IMO,The one main thing to consider it the time of year and the hot days.

One thread mentioned what was thought to be over-heating on a 100*F day.

Of course the engine will be running hotter, the air is hotter.

"But It's a Dry Heat"

I feel bad for those folks in Texas,Arizona,Nevada,S Utah,California unless they get a cold snap at 80*F.

The best test is driving in the fall or winter and see what the gauge registers then ....without any alterations to the vehicle equipment.

I bet it is close to the same spot on the gauge

 

Dont forget those of us in the oklahoma chapter!! today was the first day in a couple weeks that it was under 100 degrees, with like 27 days total this summer over a hundred, yesterday was 107*.....today was 98* with cloudy overcast and high humidity.....

 

Yup, that's right where we were. From Amarillo to about seven miles inside the OK state border on I40. Seven and a half hours to travel 80 miles or so. Once the sun went down, we were fine. Thankfully, the truck lives in Missouri and I can use it for a few months running back and forth to work with no overheating issues yet...

 

Okie Off Roader, I will have to totally agree with you on the point of running at highway speeds without a fan and having no cooling problems. We did just that once when I was living in west Texas. I had a Falcon with a broken fan blade, so I removed it and as long as the car was moving faster than about forty MPH it cooled just fine. Any slower speeds for very long and it would start heating up. I can shed a little light on your other point of having a shroud too. I have owned several Ford trucks and Broncos from 1977 to 1979. In my opinion these were some of the best Ford pick ups ever built. The standard radiator (non optional) for these trucks was adequate for most operations, but Ford made an optional radiator that was called the Super Cooler. With the standard version you would need the shroud for the truck to cool properly, especially with a 400 and larger in warmer climates. With the Super Cooler radiator you could probably get by without the shroud if you had to except in the most extreme towing or performance operations. I have done an extreme amount of trailer towing in the western US in the last thirty years and in each instance when I was towing with one of my late seventies trucks I was using the Super Cooler radiator, and I have never had not one scintilla of a heating problem. I guess what it boils (no pun intended) down to is this, if you could put a big enough radiator on it you could probably run without a shroud or a fan. It is just that each of these additional items do their part to contribute to the over all cooling requirements. This reminds me of something I once heard abut the F-4 Phantom jet fighter. "The F-4 proves once and for all that if you put big enough engines on it you could fly a brick" I guess that applies to radiators too. Since first getting introduced to the Super Cooler of the seventies I have never owned a Ford without the largest possible radiator I could get in it.

Michelle
Chelle's 56 Hauler