So yesterday i went for a little evening cruise and after i let it warm up a bit i decided on the way back i'd floor it to see how the old lady performs. I was surprised by the kick it still had until i saw white smoke coming out under the car. Uh oh. I rushed myself home to check what is was and the closer i got and thus needed to drive slower in a residential area, the more smoke it produced from under the bonnet and later even into the cabin. It was the smell of coolant. When i got home i opened the hood and smoke just came out. One of the heater hoses to the heater box (i don't know if it's called that) on the passenger side had just ruptured with a 2 inch crease in it now. The fan didn't kick in at all. When should the fan come on and how is it possible that it's just blew a hose?! the PO did plug the overflow hose from the top of the radiator but then you'd expect it to blow that hose if it was building to much pressure.

 

Hoses deteriorate. Especially inexpensive replacement hoses.
Is there any way you know how old the hose is? Maybe it was old, maybe it was defective, maybe it had rubbed some.
Lots of potential reasons, that we may never know the true source of. Just that it happens, and it happened in your case.
Without knowing how, or even why the overflow hose was plugged, we don’t know why it should have blown first.

And since none of these trucks ever came with electric fans from the factory, we don’t know why your fan didn’t come on.
They all had mechanical fans which were spinning all the time.
The later models had hydraulic fan clutches, of course, which can fail and not spin the fan with any great vigor. But even though a failing fan clutch is not uncommon, failing to the point of not spinning the fan at all would be very rare.
But it also might be the cause of your issue.

Maybe you were overheating a little due to lack of cooling. Or lack of coolant.
Or, if it’s an electric fan, two things could’ve happened.
One, a sensor could’ve failed and not turned the fan on. Or two, the loss of coolant would have not shown the sensor that it was running hot in the first place.
The sensor has to be in coolant to read it. Hot air does not read the same as liquid.
Lots of cases of fan sensors showing cool, when the engine was ready to overheat catastrophically because of a lack of coolant.

How long exactly did you drive it with the steam coming out from under the hood? It does sound like steam, and not smoke.
So the entire time it was steaming, it was losing coolant. And you were potentially damaging your engine. Or possibly even killing it.
And if it was truly steam, it was well beyond normal temperature already anyway.
When you have a normal coolant leak, it literally just spits out liquid. When it’s actually steam, it’s truly overheating and boiling over out of the leaking point into steam.
Sounds like you actually did have a major event. But without knowing more about your truck, we don’t know what caused it, or what you were experiencing.

Can you show pictures of your engine compartment?

 

WINNER WINNER CHICKEN DINNER
What he said.
Old hoses, no way to let the pressure out so something had to let go. Good thing it was not the radiator or heater core and dump coolant inside the cab.
No coolant for fan to sense if it needed to run or the fan failed and why it built up PSI and blew the weak link (hose).

People go messing with factory cooling systems that work and wonder why it over heats
Dave ----

 

I'll post a picture of the engine bay later today when i'm back home. PO probably butchered away at the car. Hopefully i'm able to restore most of it.

 

Hoses go bad that's nothing. the fact the overflow was plugged indicates it's been blowing water for a while. but that will only raise the pressure slightly as the cap will release pressure anyway .

Fix your hoses and see what happens. keep an eye on your oil, building pressure when the engine isn't overheated is the sign of a cracked head or bad head gasket.

 

If your electric fan is triggered by a sensor "in the coolant" it probably wont show much when ther isn';t any

 

So this evening i replaced both heater hoses and refilled the radiator. I let it warm up and after the thermostat opened up filled it up again. I let it idle some time and it held temperature at 90 degrees celcius constantly. Filled the radiator up again after all the air was out. Se below for a picture of the engine bay before i replaced the 2 hoses. I circled the hose where the rupture was. The fan is actually spinning like it normally should. I'm just not used to these old cars and a fan that's just spinning with the engine. You'll learn something everyday! Then th question still is... Why would the engine throw out the cooland when pushing the engine? Could it be a wrong radiator and cap maybe? I saw on the radiator written: 1967 f350 360 4spd?

 

Glad you got it fixed. Sounds like it’s working OK, so you avoided any major problems so far.

From here the hose looks like it’s under stress at an angle. Meaning, where the clamp holds the hose to the fitting, it’s at an awkward angle. And also being held down by other things pressing on the top of the hose.
I can’t tell for sure, and if you have other pictures with the hose removed, maybe we can see better. But if it’s what I think, then the hose simply wore through from stress.

Why does it do this when you’re pushing the engine?
Well, because you were pushing the engine! 😁😉
But really, two general reasons I can think of.
One is simply bad timing. It was ready to go and it finally did simply by coincidence. Serendipitous coincidence…
The other is that, when you’re pushing the engine, you are literally building more heat. A natural result of more of the power available.
And you are building more pressure at the same time. Both ambient pressure inside the radiator from the hotter coolant coming out of the hotter engine, and from physical water pressure from the faster moving water pump.
All of the above work together in any system.
I’m glad yours just wasn’t that far from home when it happened.

The markings on the radiator would seem to be from a recycle yard/source where the previous owner got a replacement radiator.
They indicate exactly the type of truck it came out of originally.

 

Situations like this and several bad stories of engines getting smoked with these cheap elec fans, is why I just finished re installing my orig.
steel fan. At lease I know if the engine is running the fan is turning.
Also, my 300 does run cooler with orig. fan even without my shroud which I am preparing to install real soon.
Glad you did not smole that engine, your lucky..

 

Any radiator without a puke tank will find a level it likes after kicking the extra out. nothing will stop it.

If it keeps doing it even without being overheated then you need to check for a compression leak.

 

I will create a temporary puke tank and remove the bolt which is in the overflow tube and place the tube in the puke tank to monitor how much coolant is being spit out. If it's reasonable nothing to worry about i think and if it throws out to much we have another issue on hand.

 

That's too much stuff under the hood going on for me .I'm more on the simple end, see everything.

 

I know! i need to check what can go and what must stay. PO made a mess under the bonnet and can't even see where everything is going.

 

You don't need a puke tank, just let it find it's level. it should be an inch or two below the neck, but if the top plate is dry that's a problem.

 

That's why i want to install al temporary puke tank to check how much it is losing.