Hi, My water is starting to run a little low in my Xsara 1.4i. What coolant is best to add - just normal tap water, deinonised water, distilled water, something else or doesnt it matter!
I have access to a distilled water still at work but the pH of the water is somewhat high at around 10 - I'd imagine that that is a bad thing and best not to use?
Cheers squelch41
I've only ever used tap water in any water-cooled engine - along with anti-freeze of course! Most modern anti-freeze mixes include things to inhibit corrosion and clogging.
If the radiator is 'running low' then the system probably hasn't been drained for a long time, and the hoses and gaskets may be in need of replacement too. Whether you do this yourself or get a garage to do it for you, make sure that you know what anti-freeze has been added, so that you can use the same stuff next time you need to top up.
If the pH is 10 then it is not "pure water" - it's somewhere between indigestion tablets and floor cleaner, and more than a little corrosive.
OK. Thanks
What Whiskers said. A mixture of tap and antifreeze. Check the colour of the antifreeze, there are a couple of different types around now which aren't mixable. Someone more knowledgeable than me will be able to tell you the difference.
IIRC distilled water is what they call aggressive in that because it is so pure, it can act as a solvent and start leaching metal away. This happened in a linear accelerator in a hospital and so the manufacturer recommend additives to prevent this. I would also question the quality of your still. pH10 is highly alkaline as I'm sure you know, it should be pH7.
OK, thansk for your advice. I think the quality of the still has been questioned quite a few times but it still seems to be there :)
squelch41
Have something to add? Share your thoughts — no account required.
Ask the community — no account required