This spring I disassembled an engine from a 1965 MGB that has been in the family for the last 30 years. It has always been filled with a 50/50 mixture of Prestone and tap water. There was virtually no rust anywhere in the cooling system. Now I am hearing that you should only use distilled or de-i…

I would imagine that it depends on your tap water, and the amount of dissolved “stuff” in it. Water quality varies a lot across the country. If you have very hard water, I suppose its possible that mineral deposits could develop and potentially clog the small conduits in a radiator, but it depends o…

It doesn’t matter what kind of water is mixed with the coolant. Be this tap water, distilled water, de-ionized water, bottled water, dog water, etc… As long as the cooling system is maintained on a regular basis, the antifreeze at the proper mixture will prevent any corrosion from ocurring. Tester …

I believe it depends on the quality (hardness) of your tap water. Personally, I only used distilled water in my cars, it is very cheap and available everyplace.

In most areas there is no problem using tap water. There are some places where the water is not so good, usually on the acid side and if it overcomes the buffers in the coolant, there can be some problems so using distilled water will not hurt. That said, I have never bothered and I would guess fe…

What they said. If the tap water is hard, it might be marginally better to use distilled water to fill. I should still be O.K., even, to flush with tap water. You will see little problem with water quality in a closed system like this compared to a chilling tower, steam boiler or water heater wh…

It’s not a problem when mixed with the correct antifreeze in your cooling system. The intent of using distilled water is to avoid minerals from the water being deposited in the cooling system.

distilled and de-ionized water is not the same. Although after doing some research I did read were Di-ionized water is preferable.

I would just buy pre-mixed antifreeze/coolant. That would easily resolve the issue. Tap water is fine though, as long as you change it on schedule. Don’t give the antifreeze/coolant chemicals a chance to stop working. Drain and refill every two years.

That is correct, I use distilled water in cooling systems. Even de-ionized water should be harmless when mixed with antifreeze containing corrosion inhibitor packages. I certainly would not use straight de-ionized water in a cooling system.

Distilled water for radiators?

Maintenance/Repairs

americar April 23, 2008, 2:36am 7

De-ionized water has no minerals in it, and there for is a sponge looking to absorb minerals, like the radiator, and other metals in the cooling system, Not what I think you would want. A matter of fact, plumbing for Di-ionized water needs to be stainless steel or plastic.

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Distilled water for radiators?

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