Replacing Cooling System With Distilled Water

[Tham]

I finally sold off my beloved Corolla KE70 a couple

of weeks ago after 14 years of ownership, and have

borrowed my elder brother's 1997 Proton Saga to use

in the meantime.

 

It has the 1,298 cc Mitsubishi 4G13 SOHC engine. Pretty

much underpowered with heavy fuel consumption.

 

I'm thinking of replacing the water in the cooling system

with distilled water, since this tends to cause lesser scaling

and rust.

 

If possible, I would not want to unscrew the radiator's bottom

drain plug, nor pull out the bottom hose, to avoid possible

leaks later on.

 

Could it be done via several times via the expansion or

overflow plastic tank, which holds about one liter, with the

expansion/contraction over a few days of running exchanging

the water ?

 

The other option might be to suck out some coolant from the

top of the radiator, replace it with distilled water, run the engine

a bit, then repeat. That would be very tedious though, since

only about 300 ml or 10 fluid ounces could be replaced each

time !

 

Thanks to the good people here who have helped me maintain

the old faithful with much good information over the years.

Edited July 29, 2010 by Tham

[altezzaclub]

Forget it!

 

The only way would be to drain it all and replace it, but it would cease to be clean distilled water the moment you tipped it into the radiator. It would instantly be dirty contaminated water. Adding a bit at a time though the overflow would never never replace all the old water, its the law of diminishing returns. Its hardest to get the last 10% out.

 

There's nothing in tap water that won't be in your distilled water after a week except the chlorine, which would vanish when it got hot.

 

Antifreeze contains sodium nitrite, which is the anti-corrosion chemical that breaks down easier than steel rusts, so it gets used up rather than the steel degrading. Just adding anti-freeze ("coolant" ) will stop it rusting.

[Sam_Q]

I have found distilled water doesnt do a good job of avoiding corrosion, just use an inhibbitier or however you spell it, so I tottaly agree with the above comment

[Tham]

Thanks for the good information.

 

I agree that it is a law of diminishing returns if one uses

the expansion tank to replace the water, and it would take

countless refills to do that, and even then that would not

really replace all the old water. The drain plug or bottom

outlet hose still has to be used.

 

Yes, I guess the solvent contamination from the copper,

aluminium and cast iron would nullify the distilled water's

purity after days of constant circulation in the cooling system.

 

I'll just leave the water and coolant in the newer car as it is.

I'll probably replace the coolant a bit later.

 

The red Toyota "Long Life Coolant" is quite popular here, though

a little expensive. However, this has organic rust inhibitors, which

I've read is more for aluminium radiators and may be corrosive to

the lead solder used in copper radiators. This car still has a copper

radiator, rather than the aluminium types in most newer cars.

[Sam_Q]

reality is most of the products on the market work well, if your pedantic then just run a more concentrated solution.

[rob83ke70]

if it is a copper/brass radiator - do NOT run red coolant, it is incompatible with your radiator, red coolant is made for aluminium radiator systems.

 

Pick a good quality green coolant/corrosion inhibitor to use.

 

I would drain as much water as you can from the radiator either via a drain plug (if it has one) or by taking the bottom radiator hose off. when you reattach the hose be careful to make sure the pipe and inside the hose are clean, and the clamp goes in exactly the same spot that it was in. I'd fill it up with water and run it until it reached normal operating temperature, then repeat process until the cooling system contains clean water. Then I'd drain it, and put the appropriate amount of coolant concentrade in to make up a 50% mixture, and top it up with water. EG if you have an 8 litre cooling system, I'd drain it and put 4 litres of coolant concentrate in, and top the rest up with water. Make sure the heater is on when you do this so you change the fluid in the heater core as well. I would run the coolant concentration at the 50% as reccommended. I wouldn't go stronger than that.

 

I'd also change it at manufacturer's reccommended intervals not the rubbish it says on the coolant bottle. Make sure its a good brand coolant too - some of the cheap nasty stuff is worse than straight water.

 

If you can use distilled water with the coolant concentrate it is better than straight water, but if its a huge hassle and your tap water isn't overly full of minerals (hard water) then I wouldn't stress too much.

 

Nothing brings out coolant leaks quite like replacing rusty water with proper coolant too - I'd be prepared to encounter a few and fix them. If you are feeling lazy, then put a bottle of wynn's radiator stop leak in with the new coolant - its meant to be pretty good.

 

I work as an automotive technician for a dealer - I really think that leaks should be repaired rather than things added to stop them though.

 

Robert.

[Tham]

Thanks for the good info, Robert. Will keep them in mind.

 

Some of the cheap locally packed coolants in Malaysia are

selling in the supermarkets at M$ 5 (A$ 1.80) a can of

300 to 500 mls !

 

I will probably order Nulon's coolant here later.

 

http://www.nulon.com.au/products/Long_Life...trated_Coolant/

 

 

Could you elaborate on this further ? Thanks.

 

Nothing brings out coolant leaks quite like replacing

rusty water with proper coolant too - I'd be prepared

to encounter a few and fix them.

 

Robert.