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Okay some advice please.

It's been stinking hot over here and I am having problems with the coolant boiling and sometimes boiling over the coolant bottle. Engine gets warm but doesn't overheat. I have recently changed the radiator to a larger all metal design and fitted a new thermostat. I have no leaks and the problem doesn't occur everyime I drive the car. :dunno:

I am going to change the fan clutch because as far as I can work out the radiator is not cooling the coolant. Any suggestions would be welcome before my old man burns my jeep to the ground and drives over it in his Nissan Patrol.

PS My 3.5 Rubicon Express lift kit gets fitted next Tuesday and I have decided on the new 32 inch Pirelli Scorpion Mud tyres.

Thanks
Rob
 

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maybe you have too much water on the system, normally it tells you to do 50/50 but I tend to use 75/25 bc of the warm weather,, also less water means less corrotion inside....:D

HTH
 

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You guys are going the wrong way.....

Too much water would cause the engine to run cooler... Water carries heat better than anti-freeze. So running a higher percentage of water in hot weather will cause the engine to actually run cooler....


But two things to think of. when the engine is cool grab the mechanical fan and see if you can spin it. If you can't or it is VERY tight, your clutch is no good. Second, you may have an air bubble trapped in the system somewhere...

:ninja:edit.... If the coolant is actually boiling, check your radiator cap. Coolant under the correct pressure should not boil....
 

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Interesting I would have thought the opposite, but I would agree that your rad cap may be going out.
If more coolant made your system run cooler... why don't they run straight coolant????

The two need to be mixed for exactly that reason... Water is much more efficient at carrying heat out of the system than Ethylene Glycol(or Polyethylene Glycol). But water has that nasty habit of turning into a solid and expanding in moderately cold temps. But water usually contains alot of stuff that is quite corrosive to soft metals, so we also need the corrosion inhibiter additives in coolant.


Folks like Belto, Rob the Aussie or you Kyle may actually never need a 50/50mix due to your lack of cold temps. The canuck crowd or the guy from Alaska may actually need to run a heavier mix of coolant because of their sub-zero temps. Where I live in the most northern portion of Illinois, we get a couple weeks of sub-zero daytime highs and some nights in the negative teens to negative 20's... A 50/50 mix is right where we want our coolant levels.
 

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If more coolant made your system run cooler... why don't they run straight coolant????

The two need to be mixed for exactly that reason... Water is much more efficient at carrying heat out of the system than Ethylene Glycol(or Polyethylene Glycol). But water has that nasty habit of turning into a solid and expanding in moderately cold temps. But water usually contains alot of stuff that is quite corrosive to soft metals, so we also need the corrosion inhibiter additives in coolant.


Folks like Belto, Rob the Aussie or you Kyle may actually never need a 50/50mix due to your lack of cold temps. The canuck crowd or the guy from Alaska may actually need to run a heavier mix of coolant because of their sub-zero temps. Where I live in the most northern portion of Illinois, we get a couple weeks of sub-zero daytime highs and some nights in the negative teens to negative 20's... A 50/50 mix is right where we want our coolant levels.
Learned something new here. Thanks whowey. ;)

I've always used 50/50 and it seems to do the job well in my region.
 

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I could have sworn that water had a lower boiling point than Glycol...
 

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Discussion Starter #10
Thanks guys/girls. I'll mess around now with a little understanding and see what happens.

Rob
 

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I could have sworn that water had a lower boiling point than Glycol...
The boiling point of water is MUCH lower than that of Ethylene Gycol. The boiling point of EG is around 190 degrees Celsius. But a mixture in a pressurized system will boil at a higher temp than one that is not pressurized.

Somehow I managed to cut-off my own message....

The issue becomes that water carries the heat out the engine MUCH more efficently than a straight Gycol fluid. This is why we want a mixture... Water for its heat transfer ability and Gycol for its ability to lower the freeze point and increase the boiling point of the mixture. Too much of either and you can have problems...
 

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You guys are going the wrong way.....

Too much water would cause the engine to run cooler... Water carries heat better than anti-freeze. So running a higher percentage of water in hot weather will cause the engine to actually run cooler....


But two things to think of. when the engine is cool grab the mechanical fan and see if you can spin it. If you can't or it is VERY tight, your clutch is no good. Second, you may have an air bubble trapped in the system somewhere...

:ninja:edit.... If the coolant is actually boiling, check your radiator cap. Coolant under the correct pressure should not boil....
Engine cool and not running.... :brickwall:

Check the coolant for carbon monoxide
 
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