ionised water

Will the use of none ionised water have a detrimental effect on Oats Antifreeze. The header tank on my 1.4 8 valve C3 is showing a red/yellow colour i.e rusty.
I suspect someone has put plain water in at some point.

alsie2 wrote:Will the use of none ionised water have a detrimental effect on Oats Antifreeze. The header tank on my 1.4 8 valve C3 is showing a red/yellow colour i.e rusty.
I suspect someone has put plain water in at some point.

Hi alsile2, potentially yes.

The trouble with 'tap' water is that it varies across the countries the C3 is sold. The calcium level is a big factor, but other impurities picked up locally or added by the water company (like flouride) or chlorine can make it difficult to say there won't be a problem with any coolant.

Using only de-ionised water (its cheap) to dilute a concentrate is the best way to go to get a known mix.

System corrosion, reduced life and a reduced protection level could be caused by impurities in the mix.

The other solution is to use pre-mixed coolant like this G30 and you don't need any de-ionised or distilled water if you have happy with the ratio (down to -36C).