Weird overheating problem!!!

WaxLyrical

WaxLyrical

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Sandton area of Brakpan
The water in my tank boils to the point where the engine starts overheating.
Water is clear and clean so it can't be the gasket.Fan switches on so it can't be the thermostat.
The fan does spin quite high to compensate for the problem though.
Did a pressure flush to remove potential blockages but it hasn't helped.
Temperaure valve inlet broke recently but just did a bypass so the water returns directly to the engine, so that can't be it.Waiting for parts to replace it.

So what could be causing the water to overheat?
 
Why arent you using antifreeze you're just rusting up the radiator. As to your question, what about the radiator cap?
 
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Flushed it and added antifreeze, although I only did that recently.
Can't access the cap, what should I be looking out for?
I'm beginning to think my radiator is shot, but how do I test it.

Not losing any water so there's definitely no leaks.
Water tank becomes like a kettle and the gauge goes into the red.

That's it.
 
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MexicanStandoff said:
Flushed it and added antifreeze, although I only did that recently.
Can't access the cap, what should I be looking out for?
I'm beginning to think my radiator is shot, but how do I test it.
Click to expand...

I would suggest you send it in to get tested but if you want to try yourself just google radiator test. With regards to the cap check that the seal is still good and the cap isnt broken or anything.
 
I'm not sure why you say it cant be the thermostat.

2 things to try is:

Let the car warm up then feel the radiator inlet and outlet, if its the thermostat or water pump the outlet will be cooler than normal(use another car to compare if you are not sure what temp it should roughly be).

Run the car for a while then switch off, open the water bottle to check if it has pressure.
 
You can't really rule out the gasket just because the water is clean.
I think they can do a test for carbon monoxide in the coolant.

Also antifreeze increases the boiling point of the water so not using any could be a problem even in summer.
 
It could be that the cooling system isn't building up any pressure, you don't mention what car it is?

You should be running a 50:50 water:antifreeze ratio

Also you can test the thermostat by removing it and suspending it (as in it shouldn't touch the pot) in a pot of water that you then bring to a boil, the thermostat should be fully open before the water begins to boil, it should have markings on it stating the temperature that it opens at, generally between 85 and 95 degrees.
 
To answer your questions:
Its Ford Bantam, and its a closed system.No cap on the radiator.
Both inlet and outlet gets hot.

There's a normal thick outlet from radiator to engine and an inlet from thermostat to radiator.
In addition there's two thin pipes one from thermostat into top of coolant tank and another linking radiator and coolant tank (which sits at the back of engine bay).
There's a third thick pipe from engine into bottom of coolant tank, and this is where the "boil" is coming from.
No leaks from radiator.

Another weird thing is that during idling and normal town driving the water boils but the temp needle stays at dead centre.
As soon as I go on the highway,the needle moves to red.
There's def pressure from the coolant tank.

I definitely need to replace something.the question is what?
Radiator.
Thermostat.
Water pump.
Gasket.

Edit:Pipe from radator bottom to thermo not hot.
 
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Not too familiar with the Bantam's, is the cap on the coolant tank one that screws on and seals the whole system?

If it is it might be the cap on there that isn't sealing causing the water to boil at a lower temperature than if it was under pressure.
 
Did you managed to get to the bottom of your overheating problems>
 
Hey there, i own a 2008 Bantam Rocam, and today it started doing the exact same thing that you have descibed in your post here, basically the water boils like a kettle, and im so confused as to how to fix it, have you found a solution please help me, i cant afford a mechanic right now, i'd rather fix it myself.
 
Hey there, i own a 2008 Bantam Rocam, and today it started doing the exact same thing that you have descibed in your post here, basically the water boils like a kettle, and im so confused as to how to fix it, have you found a solution please help me, i cant afford a mechanic right now, i'd rather fix it myself
 
From what I've read, If the water is boiling in one place before the temperature needle hits red line, then it would seem like the water isn't being circulated properly. Add it goes through the radiator, it should cool down.

I suspect either a blockage or bad water pump. What's your mileage and has the water pump ever been replaced?
 
Water pump or thermostat if not leaking water and the level is correct.
Water pump broken not circulating
Thermostat stuck or not working
Both pretty cheap and easy to repair and or replace.
I'm not a makkey but that's what I would look at first.
 
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