Using tap water as a coolant

[Marlindan1965]

I am due to give my Roadster a service soon and I was wandering what the general opinion was on the use of tap water in the cooling system as opposed to using distilled water. In both cases I mean mixed with anti-freeze as I know tap water alone would cause corrosion. I had a look on the internet the other day and some people were saying that distilled water is much better due to the fact it has no minerals in it.

Does anyone used distilled water? Do they distill in themselves or buy it? Is is best to buy an anti-freeze premix (I assume the don't use tap water for that)?

Any thoughts appreciated.

[lizbillings]

Re: Using tap water as a coolant

We have always used tap water for radiators with or without antifreeze. Only used distilled water in batteries. regards Liz

[stevejgreen]

Re: Using tap water as a coolant

My guess is that most shop bought distilled water is infact deionised water, a much cheaper process.
If you were to be constantly topping up a car radiator with tap water then the salts within each 'top-up' would gradually accumulate, but in normal service, once the salts had separted from the water, a miniscule amount, there is no further problem.
Modern antifreede contains corrosion inhibitors, but there is a little doubt over which type of antifreeze to use on an old cast iron engine over modern aluminium ones.

[peter.crowther4]

Re: Using tap water as a coolant

Distilled/deionised is the way to go and at around £4 for 5 litres from your local motor factor it's cheap enough. Tap water varies and and in many areas contains lime (hard water) , which will deposit in the waterways. As for which antifreeze, Morris universal is correct for most engines and certainly for older ones. Many of the latest generation products are not suitable as some will attack solder/copper cored rads. A search on Morris lubricants site will confirm the best product.

Pete C

[CosworthCabrioLee]

Re: Using tap water as a coolant

Slight change, has anyone used cool water or waterless coolant by Evans? If you read the write ups it's the next best thing since bread was invented. Ment to keep engine cooler, my father uses it as std in his Rotax powered air plane as std and the classic boys use it so any thoughts please ??? At £100 per shot its not cheap

No Water - No Overheating
Vintage Cool 180° has a boiling point of 180°C and will not boilover.

No Water - No Corrosion
Water contains oxygen, oxygen allows corrosion. Vintage Cool 180° eliminates corrosion.

No Water - No Pressure
Vintage Cool 180° allows your cooling system to run at a lower pressure, reducing the strain on engine components.

No Water - No Liner Pitting
Vintage Cool 180° generates significantly less pitting when compared with all water based coolants.

No Water - More BHP
Vintage Cool 180° eliminates premature detonation associated with overheating.

http://www.evanscoolants.co.uk/classic-cool-180.html

[chris_cussen]

Re: Using tap water as a coolant

Unless you are constantly topping up the radiator the quantity of deposits caused by using tap water is minute. Likewise the oxygen will be expelled from the water the first time the engine get up to running temperature. Tap water is fine unless you have a shed load of money to waste.

[FranklinLeicester]

Re: Using tap water as a coolant

When I had my rad re-cored the chap told me it was badly furred up like an old kettle. Our Severrn Trent stuff is renowned for it. He suggested using rain water from the garden water butt.

[peter.crowther4]

Re: Using tap water as a coolant

You don't mention which engine you have but I assume it will be an older Ford or BMC type. Honestly don't think there is any benefit in using the Evans coolant for your application. Stick to a good quality std antifreeze such as the Morris Universal I mentoned earlier, change every 2 years, and you will have all the protection required. With a 50% antifreeze mix you lose around 3 degrees C in cooling capability compared to plain water but provided your overall system is properly specced this will not be an issue. Ideally you want a total system capable of cooling to a max temp of 107C under maximum operating conditions in an ambient of 40 dgrees C (with 50/50 A/F mix.)

Pete C

[Dane_Rescueman]

Re: Using tap water as a coolant

I've used tap water since I started working on cars (1962). It is possible to grow a little fur but as a previous correspondent says, This is only a factor if there is a leak and the system is constantly being topped up. Come down to Cornwall, our water where I live is very soft. There is no lime scale in my 13 year old kettle. Maybe I should start selling the water to club members!!