Help with Cooling System, why am I boiling over?!!?

[KaliKid]

Hey guys, so I am running into one problem after the next. Now my cooling system is acting up and my temp is getting above 220*f and boiling over.

From the start:

I swapped my front axle and under went a lot of work getting the radiator to fit, etc. It is an aftermarket from Low Range Offroad. It is smaller than the factory radiator but not by a lot. I have had multiple small leaks that i have since patched and now it seems like maybe my water pump is bad? It seems like it isnt cycling coolant and getting so hot it is boiling out/off. I flushed the entire system yesterday and replaced all with new coolant, drove around the block today and my reserve tank busted the top off and started smoking.... Any idea? Water pump, pink milkshake, blockage?

 

[mxer]

burp it?

 

[KaliKid]

I tried to burp the system, maybe I need to do it on a steeper incline to get all the bubbles out? Should I run the system with my radiator cap off in park to burp it? I hope it is as easy as that.


Also, which way does the factory fan blow? Does it suck in toward the engine and blow air into the engine compartment or does it blow out toward the radiator? I wonder if there is a possibility i put this on backwards... ?

 

[jgue467]

A bad or going bad water pump would leak a bit out the weep hole, usually more when the engine is turned off hot/warm.

Replace the radiator cap? How do you know its getting to 220?

 

[mxer]

If it blew outward, it would be counterflow to the air rushing through the radiator when you're driving.

Wait for your system to cool. Open the cap, start the car, wait for you thermostat to open and watch the coolant flow through your radiator until all the bubbles stop, put the cap back on. As mentioned earlier a leaky cap can cause your system to depressurize and then boil.

 

[KaliKid]

A bad or going bad water pump would leak a bit out the weep hole, usually more when the engine is turned off hot/warm.

Replace the radiator cap? How do you know its getting to 220?

Well im leaking thats for sure. Especially when I flex out, it pours out!! It is a pretty good drip i have going and I feel as if it is leaking out of more than just the small fitting I know of. New radiator cap is on, I have a scan gauge.

Another question. Would I notice pink milkshake when doing the radiator flush or only if I drain the transmission fluid?

 

[mxer]

Well im leaking thats for sure. Especially when I flex out, it pours out!! It is a pretty good drip i have going and I feel as if it is leaking out of more than just the small fitting I know of. New radiator cap is on, I have a scan gauge.

Another question. Would I notice pink milkshake when doing the radiator flush or only if I drain the transmission fluid?

Your transmission wouldn't work.

 

[AZ4Running]

Air in the system, stuck thermostat or blown head gaskets

 

[KaliKid]

If it blew outward, it would be counterflow to the air rushing through the radiator when you're driving.

Wait for your system to cool. Open the cap, start the car, wait for you thermostat to open and watch the coolant flow through your radiator until all the bubbles stop, put the cap back on. As mentioned earlier a leaky cap can cause your system to depressurize and then boil.

I do know of one hole in the elbow fitting, its a slow drip. Could this cause the entire system to depressurize and boil like you are saying?

Air in the system, stuck thermostat or blown head gaskets

I hope its not a head gasket.... **** that noise

Ill be re-burping the system and replacing the thermostat after work. Any other suggestion for a good system burp or anything else I could be missing?

 

[mxer]

A slow drip when the truck is off or when it's hot? You have to maintain about 14 psig in your system.

Are you using 50/50 glycol water?

Using your data of 220 F as the boiling point...and looking at a 50/50 mixtures boiling point at 0 psig (atmospheric pressure) is 225 F and since you're at lake tahoe with an elevation of 6000 ft that bp is going to be even lower whereas if your system was at 14 psig it would boil at 263F. I would say your system isn't holding pressure either by your leaks or your cap. Open the cap and make sure you see the coolant flowing when or if the tstat opens. Open the cap when its COLD!!

 

[KaliKid]

A slow drip when the truck is off or when it's hot? You have to maintain about 14 psig in your system.

Are you using 50/50 glycol water?

Using your data of 220 F as the boiling point...and looking at a 50/50 mixtures boiling point at 0 psig (atmospheric pressure) is 225 F and since you're at lake tahoe with an elevation of 6000 ft that bp is going to be even lower whereas if your system was at 14 psig it would boil at 263F. I would say your system isn't holding pressure either by your leaks or your cap. Open the cap and make sure you see the coolant flowing when or if the tstat opens. Open the cap when its COLD!!

Yes im using the RED Asain 50/50 premix

I will try this after work. My guess is it is not cycling any fluid, could be water pump at that point. Because it is boiling before 220 - 220 is the blow off stage i guess you could call it. Might be time for an overhaul. Timing belt, pulleys, other belts, water pump and thermostat are all up for service soon anyway.... could just be it hit earlier than expected

 

[KaliKid]

After work I burped the system again, I filled up the reseviour and let it run with the radiator cap off. I waited to see when the thermostat turned on and filtered the system but it never happened. Working a desk job put me out into dark here, without a garage I wasnt able to get any further.

Orileys has a 180* OEM thermostat and a 170* after market. Im leaning toward the 170* since its lower temp rating. Any suggestions there? Also I am going to plug the small hole in the radiator hose as I think this is the cause of all this boiling as its not maintaining pressure in the system to begin with.

Has anyone ever used Radiator Stop Leak before? Does it work well? Would you suggest it?

 

[gamefreakgc]

A leak in the hose would not keep the fluid from flowing though. It's the constant flow of coolant that keeps things cool, not the temperature rating of your thermostat.

You can test your thermostat if you want to, pull it out and dip in in boiling water. If it opens, it works. If not, replace.

Pretty sure though it's like others said, your water pump is shot.

 

[jgue467]

Orileys has a 180* OEM thermostat and a 170* after market. Im leaning toward the 170* since its lower temp rating. Any suggestions there?
Has anyone ever used Radiator Stop Leak before? Does it work well? Would you suggest it?

180 = more energy efficiency.

Do Not use that crxp, it'll only CLOG things up. So new cap is how many psi?

 

[KaliKid]

A leak in the hose would not keep the fluid from flowing though. It's the constant flow of coolant that keeps things cool, not the temperature rating of your thermostat.

You can test your thermostat if you want to, pull it out and dip in in boiling water. If it opens, it works. If not, replace.

Pretty sure though it's like others said, your water pump is shot.

- I thought the thermostat was what told the system to cycle the fluid once it hits operating temp? Im not overheating at all on the in car gauge...

180 = more energy efficiency.

Do Not use that crxp, it'll only CLOG things up. So new cap is how many psi?

Im not sure of the new cap PSI rating but it hasnt blown off or anything..

 

[gamefreakgc]

- I thought the thermostat was what told the system to cycle the fluid once it hits operating temp? Im not overheating at all on the in car gauge...

The in car gauge will only turn to red once the temp is high enough to destroy the engine. It's more of a "you just ruined your 4Runner" gauge than an accurate gauge of temperature. The cap is supposed to release pressure before it gets that high, via the reservoir or bypass hosing if you have it.

Yes, the thermostat is what allows the fluid to flow. However it's just a simple device filled with wax that expands with heat, no fancy contraptions on it. So if you're not seeing any flow in the radiator (you should see fluid sweep across the top) that leaves two possible components, bad thermostat or bad water pump. Even with a small leak, the coolant will still flow.

 

[KaliKid]

The in car gauge will only turn to red once the temp is high enough to destroy the engine. It's more of a "you just ruined your 4Runner" gauge than an accurate gauge of temperature. The cap is supposed to release pressure before it gets that high, via the reservoir or bypass hosing if you have it.

Yes, the thermostat is what allows the fluid to flow. However it's just a simple device filled with wax that expands with heat, no fancy contraptions on it. So if you're not seeing any flow in the radiator (you should see fluid sweep across the top) that leaves two possible components, bad thermostat or bad water pump. Even with a small leak, the coolant will still flow.

I ended up replacing the thermostat and Radiator cap, and getting rid of my radiator leak. Something along the way solved my problem and im running at normal operating temp now. Thanks for all your help guys. For $20 I am up and running as good as new. Now onto the next thing.

 

[gamefreakgc]

Sweet! That's what we like to hear, the easy and cheap fixes did the trick!

 

[Stickma2]

11 yrs after original post, same issue. What fixed it?

 

[Hungryhawk]

I recommend NOT using stop leak products.
Too many things get gummed up.
Check your pressure cap settings, check your thermostat-they do not age well. I would try to find both specs for your year & model and get those. As said earlier verify the coolant. Premix or pure mixed with distilled water. Keep tap water and its minerals out of the system.
Is your heater core plugged or open?