I used to boil water for a living¸ a LOT of water. I worked at a steam electric generating station. My whole day was all about heat exchange. Adding heat to water¸ taking heat away from rotating machinery. I learned a little about keeping things cool doing it so I am adding this wisdom to what I know about cars and writing this page to give you my viewpoint on keeping your XJ (or any other engine) cool.

I knew when I bought my Cherokee I wanted a Three core Radiator. I got mine at Radiator.com for $120.00 including shipping.

I had cooling problems when I first got the thing which helped with the decision to replace the Radiator right away. The thing always was over 215 degrees on the gauge. When I drained the coolant and put the flush fluid in¸ the engine ran below 210 degrees. This remained for as long as I had just water in the old radiator. which brings me to the point of writing this page.

There is a good write up on Cherokee America about changing out your radiator¸ but I disagree with a couple of the points the author made. Both are in the same sentince¸ he suggests using Dexcool because it leaves fewer deposits in your radiator.

First¸ I don't like Dexcool. Not because it doesn't work. But when you are out in the boonies you better have your own supply. Not everyone stocks Dexcool. And if you mix it with Etheline Glycol (the green stuff we are all used to) it makes sludge in your radiator.

Second¸ sludge does not come from coolant. The coolant does two things. First it lowers you freeze point and raises the boiling point of the water in your radiator. If you live where it NEVER freezes you could run straight water and have better cooling. (This is because water has a higher specific temperature than antifreeze. That is pound for pound¸ it takes more heat to raise it's temperature one degree than it does to raise the temp of antifreeze.) You would however need to add something like water wetter to preven corrosion and lube your water pump. The Radiator cap also raises the boiling point of water so this part of it I think is a wash. With water only you would run cooler and not need to be as concerned about boil over. If your system is marginal however¸ or you don't keep an eye on your temp. gauge¸ you could still get boilover.
That being said¸ antifreezes second job is to PREVENT CORROSION. Do you think that they could continue to sell the green stuff If it CAUSED what it was meant to prevent? SO where do the deposits come from?? Why the water of course! Does anybody you know have a water softener? Water carries with it Minerals¸ iron¸ calcium¸ zinc¸ phosphorus and the like. When you heat the water they want to fall out of suspension. Thus you get the gook in you radiator. Have you seen the picture some shops have of clogged radiators? Most of the deposits are white¸ that's mostly calcium from the water mixed with some of the other minerals in the water we drink (don't worry WE actuall need these minerals)

Now¸ how do you prevent this you ask? Good question! And a simple one to answer. Use Distilled water only in your radiator. Some places only have ¨purified¨ water now a days¸ this is OK as well. They just used a different and simpler operation (Reverse Osmossis) to remove the minerals from the water.
Now when I say only used distilled water in your radiator I mean when you flush it as well. When you drain the thing there is always some water left¸ and if you got that water out of the hose you got the minerals with that. Yes they would be less that if you didn't fill with the hose¸ but we don't want any of those solids in our radiator at all.
When I Flushed my radiator¸ I drained and filled it six times to get the fluid running clear. I used about 14 gallons of distilled water to do this. It only cost me 58 cents a gallon¸ so the added money to the new radiator is very small compared to the fact that I now do not have to worry about it clogging on me.

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