Radiator Boiling Over

[pb4ugo]

Correct, it's a siphon. Your IV is doing the same thing the tank does. The tube your iv is connected to needs to be submerged in the coolant when it's in the tank. It will force the air/fluid out and suck fluid in just like your iv.

When it overheated, did it have a tstat or not?

 

[73FJ40]

Your OEM overflow tank has a "cold" level marker on its side. If you fill the overflow tank to that level, then when the engine heats up, fluid expansion will raise the level in the overflow tank. When things cool off, the overflow tank level should return to the "cold" level.

It's difficult for anyone commenting here, to understand why you are compelled to use that orange juice bottle in lieu of the OEM overflow tank.

 

[AYM707]

All you need to do…

1. Properly bleed system with bleeder on radiator until stable.
2. Confirm upper hose pressurizes when hot lower hose is warm but not hot at operating temp.
3. Perform compression test hot and cold for comparison.
4. Tell us if it continues to boil, if it does either your water pump or tstat is failing or your hg is leaking.

Checked the hot / cold pipes. used a temperature gun to measure outside temp's. The hot side was 60C and the cold was only 57C. What is the typical temp delta? I think the radiator has to go.

 

[Skreddy]

It’s already been said but….

Put a new, good radiator cap on it and put the thermostat back in with the correct o ring inside the housing.

You may have an actual issue but you won’t know until you baseline with a proper system.

Steam in exhaust is common especially if it’s not running long enough to bake all the moisture out of the exhaust. Also, if your overflow or IV bottle is too full, there’s nowhere for the expanding coolant to go so it dumps on the ground.

 

[73FJ40]

Must be ultra high altitude to boil over at 60 deg C (140 deg F).

Maybe OP isn't reading what's been stated..

 

[pb4ugo]

He's not running a tstat, it would take forever to get it to operating temp. It could be the rad, but do what @Skreddy said 1st.
The overflow isn't the problem.

 

[73FJ40]

He's not running a tstat, it would take forever to get it to operating temp. It could be the rad, but do what @Skreddy said 1st.
The overflow isn't the problem.

Quote from post #1:

"After a 45 / 60 min drive normal highway; my radiator fluid is boiling / overflowing from reserve tank release."

In retrospect, who knows what this really means...

 

[pb4ugo]

Someone pulled the tstat for a reason.

 

[AYM707]

He's not running a tstat, it would take forever to get it to operating temp. It could be the rad, but do what @Skreddy said 1st.
The overflow isn't the problem.

Quote from post #1:

"After a 45 / 60 min drive normal highway; my radiator fluid is boiling / overflowing from reserve tank release."

In retrospect, who knows what this really means...

I'm sorry guys...but in the Middle East, most vehicles do not run with thermostats. When ambient temperature +45-50C and you're stuck in traffic, you need max coolant flow through the engine / radiator. This is recommended manufacturer approach, even in current vehicles. I've been driving around the Middle East for 8 years in this truck with no thermostat and no boiling / heating issues. So its definitely not the problem here.

As now I'm in Canada, I dont have a problem reaching "operating temperature", my problem is maintaining that level; as its over heating. ..hence my #1 statement.... "After a 45 / 60 min drive normal highway; my radiator fluid is boiling / overflowing from reserve tank release.".....the comment " Part of this problem, I think was attributed to air within the system and its expansion. That's why I made the air vent "IV" to draw out the air & replace it with coolant, when it cools. Yes, it operates similar to the reserve tank, as in a piping system, air is typically trapped at high points. My tank volume is a bit bigger than my reserve tank; to accommodate the initial expansion of the fluid and then when air released & the fluid cools, suck fluid back into the system.

Going back to what @mattressking wrote :

All you need to do…

1. Properly bleed system with bleeder on radiator until stable.
2. Confirm upper hose pressurizes when hot lower hose is warm but not hot at operating temp.
3. Perform compression test hot and cold for comparison.
4. Tell us if it continues to boil, if it does either your water pump or tstat is failing or your hg is leaking.

Item # 2 was basically to check the temperature delta across the radiator. I was barely getting a 3C delta; which I think implies that my radiator is dead / needs replacement? What's the typical delta on a standard original radiator?

 

[bobm]

My 78 Fj40 had a similar issue, after a couple hours of driving it would piss out antifreeze. Never indicating Hot but would just piss it out! I tried everything, full system flush with petcock on block opened, new T stat, and everything I could think of without change. So tapped and helicoiled T stat housing with stainless helicoils and bolts. Removed T stat in Summer and installed back in Winter and was all set. Never had that happen before but my Fj40 liked it and thats how I ran it for years

 

[AYM707]

Just wanted to close the loop on this thread.

I replaced the radiator with another. (Donor vehicle was a 1982 FJ40 from KSA). After flushing / burping the system, I stress tested the vehicle; the engine was choked / rev'ed and ran for about 30 min and there was no / limited impact to the temperature. I checked the gauge and cross-checked using a laser thermo-gun. I did the same test with the older radiator, and within 25-30 min's the FJ45 was running very hot. I've saved the old radiator as I was told it can be re-cored. If anyone wants it, give me a shout.

I checked the intake / exhaust valves clearances. There were several valves that were too tight and 1/2 that were lose. Now everything is as per spec.

I also did a compression test, as recommended by @mattressking . 5 cylinders were at 140 PSI and the 6th was as 143 PSI; so I dont think there are any issues / concerns there. Just to make sure I did the compression test correct, individually I cranked the vehicle, to a count of 5, repeated 3 times per cylinder. Ignition coil & fuel supply was discounted.

I have not taken the FJ45 for a long drive, cause its too cold, looking forward to spring.

 

[mattressking]

Just wanted to close the loop on this thread.

I replaced the radiator with another. (Donor vehicle was a 1982 FJ40 from KSA). After flushing / burping the system, I stress tested the vehicle; the engine was choked / rev'ed and ran for about 30 min and there was no / limited impact to the temperature. I checked the gauge and cross-checked using a laser thermo-gun. I did the same test with the older radiator, and within 25-30 min's the FJ45 was running very hot. I've saved the old radiator as I was told it can be re-cored. If anyone wants it, give me a shout.

I checked the intake / exhaust valves clearances. There were several valves that were too tight and 1/2 that were lose. Now everything is as per spec.

I also did a compression test, as recommended by @mattressking . 5 cylinders were at 140 PSI and the 6th was as 143 PSI; so I dont think there are any issues / concerns there. Just to make sure I did the compression test correct, individually I cranked the vehicle, to a count of 5, repeated 3 times per cylinder. Ignition coil & fuel supply was discounted.

I have not taken the FJ45 for a long drive, cause its too cold, looking forward to spring.

Pedal to the floor for WOT?

 

[charliemeyer007]

The voice in my head that drives my heel

 

[AYM707]

Pedal to the floor for WOT?

yes, forgot to mention, i slowly pressed the pedal to the floor. each time.