Lotus Elan and Lotus Elan Plus 2 Forums

Is it ok to use tap water when you change the antifreeze or must you use de-ionised? I live in a hard water area if that makes any difference.

You can buy the Coolant/Antifreeze that you don't need to mix with water.
I use an Etylene Glycol coolant and no need to add water.
When you drain the Cooling System try to drain 100%.
That means remove hoses for Heater at the Engine end and blowed copressed air in heater Hose at Thermostat to empty heater Mattrix. Maybe you could flush heater through first. You will be surprised at the dirt that comes out.
Alan

Well at £3.90 for 5litres from Halfords for de-ionised water I wouldn't have thought would break the bank anyway so why the concern?
https://www.halfords.com/motoring/batte ... x2EALw_wcB

Alan.

It depends on your local tap water quality and specifically its amount of various dissolved salts ( also called "hard water" if lots of dissolved salt ions). In Melbourne its not a problem as our tap water quality is very low in salts, but that is not common around the world. I would buy deionised water to add to concentrate or buy the pre diluted coolant in most of the world.

cheers
Rohan

In West Sussex and Hampshire the water is very hard.
Where William lives. Lived most of my life in or near Portsmouth. Always changing Tap washers and Descaling the Kettle a real pain.
Car Rads love it So do Windscreen Washers
Alan

Use rain water!

Craven wrote:Use rain water!

Yes just park you're DHC Elan outside for a few days with the top up and then drain the water leaks from the floor drain plugs

cheers
Rohan

William2 wrote:Is it ok to use tap water when you change the antifreeze or must you use de-ionised? I live in a hard water area if that makes any difference.

Regrettably I used just water, without additives, for many years and it was a big mistake. Without the lubrication effect of the additives the water pump seals don't last very long and without the anti-aluminium corrosion additive you get problems with the head and corrosion of the water outlet on the front cover.

I always use de-ionised water with anti-freeze, about £1.50 for 2.5 ltrs from Asda. Mix that with a good brand of ant-freeze and you're good to go. I have two Twincams with AL2 heads, the Lotus, and an Alfa 105, so imperative to use as above to keep things right.

I use the water from my dehumidifier, you could also use condensate from many tumble driers.

That's a great idea, I've got a dehumidifier running in my garage. Thanks.