Gurgle Sound in Rad/OverFlow (1 Viewer)

[RyanCostaRica]

Hey guys, here is the story, I live on a very rough road, and every time i drive over bumps my overflow leaks from the Top Cap. So I am constantly filling it back up with h20, I dont use Rad Fluid as it is the Tropics here.
Now every once in a while, twice in the last few months I notice when I get home the rad and overflow are gurlging, if I unscrew the rad cap a bunch of air builds, the skinny hose was soft and then after I did that it went hard. My rad level is always topped up, its just the overflow that needs to be added... Wondering if I should replace my HG or Thermostat or if its simoly due to the huge bumps that could be potentially be causing air to be sucked in? She never over heats on long hauls...any advice would be great, thinking on switching the HG regardless and perhaps the therm as well.

 

[sometlc]

Your motor still needs coolant. water boils at a lower temperature.

 

[sometlc]

As it all heats up it expands and fills the overflow. when it cools it will empty the overflow.

 

[RyanCostaRica]

It's not readily avail here. I know sounds crazy....I did notice the rad cap was cold until I unscrewed it a bit then it got hot.


Proud owner of Beast. 77 BJ40

 

[RyanCostaRica]

Right ok, is there anyway I can test the HG? The rad doesn't leak...but yes perhaps when the water expands it is creating pressure back in the over flow?


Proud owner of Beast. 77 BJ40

 

[sometlc]

Your overflow is an expansion tank, when the fluid heats it expands and fills into the overflow(expansion tank). So when it is cool the overflow needs to be empty. The gurgling sound is the fluid boiling from overheating. If you only have h20 in your system then it will boil ay too low of a temperature. I would start there.

 

[sometlc]

If your head gasket was an issue you would see signs in other places like your exhaust or in your oil.

 

[sometlc]

Boiling water = steam. Steam can escape and lower your level in your rad.

 

[RyanCostaRica]

Ok I just had oil change no sign of H20 etc.
this is weird but if I start my trip with overflow empty the car gets quite hot. But if I fill to the max before it is fine. So clearly I need to be using coolant? To be clear this is the overflow correct?

the problem with using coolant is that the overflow with spill it all out.


Proud owner of Beast. 77 BJ40

 

[RyanCostaRica]

I just noticed my fan doesn't turn when I try to move it. That's not good. My mechanic knew that but said it wasn't a big deal. Clearly it is....


Proud owner of Beast. 77 BJ40

 

[Canarias]

I live in subtropics and people use tapwater in their rads here too. Head gaskets and welding cracked heads make up a large portion of the local economy. Put some "coolant" in and don´t use tapwater cos it will cause a calcium build up. Mix coolant with distilled water.

 

[JohnVee]

Coolant mixed with water has a boiling point well above the 212*F boiling point of plain water. It will most likely not boil over and spill out of the overflow because it most likely won't reach it's boiling point. Especially when you fix your fan clutch.

1. Does your fan run at all while the engine is running?
2. Post a pic of your temp gauge when your engine is at operating temp.
3. FYI, if you run it with water-only in Canada you're gonna be in for an expensive surprise.

 

[RyanCostaRica]

Thanks for the info John. Here's the kicker my temp gauge works only when it is in the mood so ill start by replacing that and fixing the fan.


Proud owner of Beast. 77 BJ40

 

[sggoat]

If you keep having to add coolant(water, or antifreeze) after you drive it, then you have a leak somewhere. Easy to check to see if there is a leak--look under the truck- if no evidence of leak there, you could have a head gasket leak, and the water is being steamed in the engine- to be exhausted in the valve cover, or the cylinders somewhere. This is why you should use an antifreeze type coolant--it will elevate the boiling point of the mixture in the cooling system, helping to prevent "steaming" in the system.
The system is closed, so when the engine gets to op temp, the water will expand somewhat, and push into the overflow bottle through the rad cap(it should be rated around 10PSI or so). When the engine is stopped, the temps will initially rise, then drop, drawing coolant back into the rad.--net is zero--except for very, very little over time due to evaporation(maybe a 1/2 cup?)
If you are experiencing boiling and blowout of coolant in the overflow bottle, it could be you have a head gasket leak(my 77 showed the same symptoms)

 

[chevurai]

Check that radiator cap is functioning and is the correct pressure. Heating, expanding fluid that flows into the overflow, and cooling, fluid is drawn back into the radiator, is a normal process. A bad cap may expel the fluid at too low a pressure and not draw it back in.

 

[RyanCostaRica]

Ya my problem is the overflow keeps leaking from the cap every time I go over huge bumps. My road is horrible and my ride bumpy so fluid keeps jumping out of the overflow.



Proud owner of Beast. 77 BJ40

 

[JohnVee]

I don't think that your overflow bottle should be filling up that much to spill out of the top unless you're overheating or have a bad rad cap (which can cause overheating). Look up the proper PSI for the cap and check the stamp on yours; I think it's 9psi? You really need to address the temp gauge issue first so that you know what you're dealing with. Rudi's thread on gauges, clusters, etc is a long but IMPORTANT read. Do that before you go replacing anything.

I'll ask again...does your fan run while the engine is running?

 

[bj40green]

Coolant is also a anti corrosion product. Coolant with distilled water 50/50 is recommended.
Check your thermostat if you have one. It's very common here in the tropics that you have none. Somebody threw it out.
Check your radiator cap for proper functioning. It should open when the pressure is too high and suck the coolant back in from the overflow tank when the engine cools down.
That overflow tank is not OEM but should have at least a tube attached so that the coolant is dumped on the ground and not spitting around in the engine compartment.
If you have been working on your coolant system, you'll likely have an air bubble in the system. This bubble will push more coolant out than necessary. This also causes the sucking sound that you hear when you remove the radiator cap.
Make sure that the nose is higher than the back. Jack it up, drive up the sidewalk, whatever.
Let the engine run and getting at work temperature with the radiator cap off until no more air bubbles appear.
A working gauge will help.
On our BJ's here in Costa Rica we have a "fixed" fan which means it will always turn, unless a PO did a modification or something else is wrong.

Rudi

Oh, and don't believe your mechanic.

 

[sometlc]

Rad cap is a cheap replacement. Water without coolant is an obvious problem. Fix the obvious and go from there. If you continue to drive with only water you will have much harder issues to fix.

 

[subzali]

I don't lose an appreciable amount of coolant after a day of wheeling, so not sure your rough road is a good excuse.

If that cap is on securely then liquids will have a hard time finding their way out of the overflow bottle anyway.

Curious how you get our radiator cap off after driving it - very carefully I suppose? When you do that and depressurize the system you will get bubbling/boiling almost for certain.

Also pretty sure that a fixed fan is typical for a 77 of any variety (except maybe CA smog models), so if your fan is not turning that may be something else to look at.

So I guess this post probably isn't that helpful. Head gasket leaks can be evident by water/milky froth in the oil fill cap area, steam cleaned spark plugs (unless you said you have a diesel), leak down test results, etc. so would t jump to that conclusion unless other tests are positive as well

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