Bubbling in Radiator

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Long Duck Dong

10 Year 15 Year
Joined
Sep 10, 2006
Threads
18
Messages
162
Location
Albertville, Alabama
Hi Guys,

Stayed home today to get some work done around the house I have been neglecting. I had to jump start an old car of our we havent driven in months, anyway my LX sat at idle for about 20 min before I got around to opening the hood and hooking up the jumper cables. Jump the other car off and backed the LX back into my garage and shut it down.

After I shut it down I heard like a bubbling/boiling sound coming from the front of the truck, popped the hood and Anti Freeze in the overflow was boiling......should I be concerned? I have never noticed this before.... Prior to jumping off the other car I hooked up my boat and pulled it back to my stereo store to store it for winter....would the stress of pulling the boat cause this???......:confused: :confused: :confused:
 
temp gauge is normal .... It's not over heating.....My guess was fan clutch....
 
A bad radiator cap would do that?

Hmm, that makes me wonder if the cap is bad in the used radiator I installed and that caused the coolant to force its way out of the upper hose connection to the radiator?

I should probably swap caps now that I'm completely paranoid.

Is there any way to test a cap?

My guage never moved at all into hot and the fluid was just pressuring its way out.
 
A bad radiator cap? .... seriously?

Wow, I would have never thought that one, but I will try it...
 
CodyRx7 said:
A bad radiator cap would do that?

Hmm, that makes me wonder if the cap is bad in the used radiator I installed and that caused the coolant to force its way out of the upper hose connection to the radiator?

I should probably swap caps now that I'm completely paranoid.

Is there any way to test a cap?

My guage never moved at all into hot and the fluid was just pressuring its way out.
Click to expand...

You do understand how the radiator cap and the overflow hose/reservoir work, right?

Curtis
 
not really, please explain....
 
When the fluid in the cooling system heats up, it expands, causing the pressure to build up. The cap is the only place where this pressure can escape, so the setting of the spring on the cap determines the maximum pressure in the cooling system. When the pressure reaches 15 psi, the pressure pushes the valve open, allowing coolant to escape from the cooling system. This coolant flows through the overflow tube into the bottom of the overflow tank. This arrangement keeps air out of the system. When the radiator cools back down, a vacuum is created in the cooling system that pulls open another spring loaded valve, sucking water back in from the bottom of the overflow tank to replace the water that was expelled.
Click to expand...

(from How Stuff Works.com)
 
Ironically, the rad cap is the easiest part of the cooling system to change, and the cheapest - yet if it is not operating correctly the entire system fails. I'd buy a new OEM cap and let the truck idle for 20 mins after proper refill to see if it happens. Was the used rad cleaned before install??

DougM
 
I tossed on the old cap that I knew worked on the radiator and drove for maybe 50 miles round trip this afternoon and no leaks anywhere.

I still had a little bit of a hot coolant smell but thats the residual stuff that made it onto the exhaust manifold mud and will bake for me for many days to come.

Actually, most of the smell went away after the drive.
 
Long Duck Dong said:
temp gauge is normal .... It's not over heating.....My guess was fan clutch....
Click to expand...

Fix the gauge, it is worthless stock as it is so heavly padded it doesn't move from 150-225f. If you look under the faq, there is a writeup by raventai on what components are necessary to make it work, they cost about $5 and it only takes about an hour of time and a soldering gun. For you, it will be so boring and easy it will be hard not to fall asleep.
 
Long Duck Dong said:
A bad radiator cap? .... seriously?

Wow, I would have never thought that one, but I will try it...
Click to expand...

Yes -- absolutely. You can learn from my mistake right here:

https://forum.ih8mud.com/showthread.php?t=107319

I could have saved myself and other members a lot of grief by simply changing the rad cap. I thought it had already been done, but didn't follow up to be sure.

Ed
 
CodyRx7 said:
...a vacuum is created in the cooling system that pulls open another spring loaded valve...,[/quote]

Regarding this post, where is this another spring loaded valve located? Is this the same as the sprin valve in the rad cap?

I can't imagine how there could be a spring on the overflow cap so I'm guessing this another spring loaded valve is located somewhere else.
Click to expand...
 
Could be a partially clogged radiator core. That is the issue that caused my coolant overflow to boil last summer. It overheated mildly at first but gradually worsened on extended drives and had to be shut down.
 
podiev said:
CodyRx7 said:
...a vacuum is created in the cooling system that pulls open another spring loaded valve...,[/quote]

Regarding this post, where is this another spring loaded valve located? Is this the same as the sprin valve in the rad cap?

I can't imagine how there could be a spring on the overflow cap so I'm guessing this another spring loaded valve is located somewhere else.
Click to expand...


One spring in the cap releases fluid from the radiator when 13-psi is reached; another (yes in the cap) allows fluid back in at any sign of vacuum in the rad.

Y 4 U ask?

Curtis
Click to expand...
 
So both springs are in the radiator cap?

I asked because last night, I replaced my radiator cap with a new OEM. Previous one has the rubber seals slightly worned out.
I noticed then that my overflow tank has about 2 inches more than the full line. Previously, my coolant level at the ovelflow tank remains constant at the full line - it never dipped nor increased. So I transferred back the difference into the radiator using a suction hose and put on the new rad cap.

Then I searched mud this morning as to possible culprits as to why my overflow level should increase. And I saw this post and made me think: Maybe that 2nd spring valve is not working hence coolant in the overflow tank is not being pulled back to the radiator after engine shutdown. But to my untrained eye, I can only see one spring in the radiator cap. Hence the question when I saw this post that there are two spring valves.

Is more coolant in the overflow tank caused by a defective radiator cap? Or something else I should worry about?

I did not test drive the LC last night - will have to wait till the weekend to see what happens to my coolant level after replacing the cap.
 
Suck on the bottom of the rad. cap (no I'm not kidding or trying to be rude) and you'll see that it's meant to allow coolant back into the rad. at any sign of vacuum. The large spring, on the other hand, allows coolant out only under serious (13psi, IIRC) pressure.

Water/coolant expands significantly when heated, and the rad. cap/overflow bottle system is an ingenious way to deal with this. Try the following: Start your rig in the morning with the hood up, and watch the cooling system. As the engine warms, the upper hose to the radiator should start to get warm and stiff (hah!) as pressure builds. Once 13psi is reached, coolant should start to flow to the overflow, and the level in the overflow should slowly rise an inch or so. (This should all take about 5-10 minutes.) If you then go for a drive, the overflow level should remain relatively constant. Next, when you shut off the motor, the process is reversed, only much more slowly; as the engine cools, pressure is relieved in the rad., and coolant is slowly sucked back in from the overflow. (This process takes 1-2 hours or more.) Finally, once the engine is completely cooled, you're (hopefully!) right back where you were first thing in the morning.

Hope that helps,

Curtis
 
CJF,

Thanks for the tip - will test this Saturday morning and advise of the results.

However, what happens if on Sunday morning I still have more coolant in the overflow than what I used to have on Saturday morning prior top the test? What does this situation indicate? What else should I check/repair?
 
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