Hi again! 🤣
my 1985 Ford F350 with a 460 overheated on the way home last night. I happened to look at the guage and it was at the high normal and climbing. I immediately stopped the truck. No indication of any leaks and both the reservoir and radiator was full. I let the engine cool almost completely started the truck and started to drive and it started to heat up again. I stopped and had a friend tow me home.
I’m assuming it’s a stuck thermostat which is an easy cheap fix. What temp rating should I get? Also, since I’ll be working on my truck should I go ahead and replace the water pump, clutch fan, radiator and hoses? If recommended is an aluminum radiator best? Which one?
thank you yet again for all your help…invaluable!
Larry

 

The parts store should know what temp stat but as a guess most likely 195*
That should give you some needed heat on them cold WY days you get.

As for the rest some is high dollar items.
Radiator if you look down inside do you see crud around the tubes and has the motor been running a little hotter that normal from years ago?
No crud and not hotter then I would keep what I got.

Same goes for the fan assy and water pump and maybe more so with todays parts as some are bad out of the box.
Why replace good parts?

Now hoses are a different story as they go bad from the inside out so cant be seen if good or bad.
Do you know how old they are and over all do they look good, not soaked in oil or gas?
If you replace the lower hose most if not all new ones dont come with a spring you have to use the spring from the old lower hose.
If you dont install a spring in the lower hose when the RPM goes up the pump sucks the lower hose closed and you get no coolant flow and over heat.

On the stat I drill a 1/8" hole to let air pass thru so burping is a lot easier.
Some also test the new stat in a pot of boiling water to make sure it opens but who's to say it will open after that?
Dave ----
ps my 02 Durango with 283K I dont ever remember the hoses being replaced by the dealer when serviced and I never did change them and they look great.

 

Thank you! Hoses look fine, but may consider changing them because it’s sorta cheap. I’ll take your suggestion on the 195 degree thermostat, but still ask at Oreillys. The only reason I was considering swapping everything out is just to start fresh. I drive the truck a few times each week. The guy I purchased the truck from built it from 2 truck…1985 and 1986. He seems to have done a good job, but I often wonder if he took the cheapest route because of some other issues I’ve resolved. I’d just hate to get up hunting towards Yellowstone and have another overheating issue.
Larry

 

195 is OE temp for your 460. No need to drill any holes. How's your coolant? If its getting old, (acidic) or weak concentration it's a good time to do a distilled water flush and new coolant. Remove the thermostat and check it in a pot of water with a thermometer. I use a meat thermometer. Then you can verify any issues with it. Visually you might be able to see the issue too. In your case a sudden over heating means it was no longer opening up at temp.

If you are going to aluminum radiator you will likely be changing coolant type assuming you have a copper and brass now.

 

Remember to keep the spring from the bottom hose and put it in the new lower hose. I see Dave talked about that too. Just don't forget it.

Just be careful with stuff from Oreillys, Others have had issues using parts from them. When it comes to important stuff like a good running truck, don't buy the cheap parts.

 

BigBlue how does air get pass the stat till it opens and pukes out the fill and the fan blowing it all over?

With the 1/8 hole it is big enough to let the air thru but still hold coolant and keep the temp at 195*
If a stat gets installed to the face of the head or intake put the hole at the top.
To each his own I guess
Dave ----

 

I'm not exactly sure why you need a hole. Are you needing the hole for the filling or the draining? I've never done that or needed a hole in my thermostat for draining lift the thermostat, but it's always been dry under for me. For filling you have to get as much coolant in as you can, then warm the engine to burp air and top off.

Now I did have a buddy who had a stuck closed T stat and he was out in the bush overheating so drilled a hole in the stat to get him back to civilization.

Maybe I'm not understanding your hole theory or the need?

 

It is for filling.
As you are filling the coolant fills from the bottom up and if the stat is installed air is trapped behind it,
With the 1/8 hole the air can pass thru back to the radiator and when it is full it is full most of the time.
Also with out the hole when the stat opens and it burps it pushes coolant out the radiator before it can pull it thru the motor.
Then the level drops really low and you need to top it off more.

I also have 2 dogs and anti freeze on the ground is not good as they like to lick it or their paws if they walk thru it so the less that pukes out the better.
Give it a try next time as it cant hurt.
Dave ----

 

Dave, most of the thermostats I have bought in the last decade all are "Fail Safe" locking design but also already have an approx 1/8" hole with a brass dongle in the hole. The dongle helps to breaks up any debris/contaminants while air/coolant can always pass through the small opening even when the Stat is closed. Where are you getting "old school" thermostats that don't lock open when too hot and don't have the hole in them already?

 

I've never had an issue filling or spilling as I put the rad cap back on between warming and topping. Don't want fido licking up the spill.

 

Besides the crappy factory gauge going wonky, how do you know it's overheating? You said there were no other signs. Are you going ahead and spending a bunch of time and money on it because of what the iffy factory gauge tells you? I think I would get a second opinion with a infarad thermometer or a aftermarket temp gauge.

 

Even an after market guage can be faulty. And Dave says he's gone through several. But you should be able to tell if it's over heating by placing your "calibrated" finger tips on the top hose. I know what that feels like. But if you don't know the infrared thermometers are a good check. Then you can use it on your BBQ too. Your issue could be a bad sending unit or a loose connection. My stock guage has worked flawlessly for 37 years. I recently replaced my sending unit and it works good as new.

 

Local parts store and the last 2 for my 300 six did not have the bleed hole.
As for lock open I cant say. What happens when tested dose it stay open after it cools?
If not then how do you know it will open the next time it gets up to temp?
I have only had 1 stat fail to open. That was on my drag car on motor break in and it worked 2 weeks before.
I ended up removing the center & spring and used it as a washer slowing the flow and it worked great.
BTW they sell different size center hole washers to just for stat replacement so you dont get a fail to open stat putting you out of a race.

I dont like opening a warm or hot radiator. If it is not cold to the touch it stays closed, I like my skin way too much
Dave ----

 

Dave, the T-stats for my 6.9l diesel are different than ones I've typically used. In 400 k miles I've changed two, but they were a year apart, so the first one bit the dust after 1500 mi. I'm not inclined to drill a hole in these types. Look up a photo on line and you'll see.

I don't open my rad cap till it cools enough so it doesn't spit. It doesn't take longer than about 1 cup of Joe or one .

I know how to do it. But kids if you're watching don't try this at home....

 

Thank you! Do you recommend a specific aluminum radiator?