Coolant turning into Clear colour

[MITSIR]

Hi Guys,

I had a check at the Coolant Reserve Bottle next to the Radiator, and the Coolant Water has gone to a clear Colour. Strange.

I took the Water out of the bottle and filled it up with coolant mix again. Checked this after a few days and guess what. The Green colour had dissolved and back to clear. Plus the Coolant in the Radiator doesn't look that green aswell.

I had replaced the Coolant 1 year ago and added a stornger mix of coolant to water Ratio as instruted on the Bottle.

Would anyone have any Ideas on why this would happen?

I'm using Nulon Long life coolant. Can it be the wrong type of coolant that I'm using?

[Eastie]

Is there a chance that you've mixed different coolants together?
I've seen coolant lose some color (not go clear though) when different coolants/inhibitors where mixed. The explanation was that different (chemical) types of coolants can react, creting salts and other undersirables leading to changes in the physical and chemical properties of the coolant in the system. This can lead to premature failure of cooling system components (restriction of the radiator fins from salts, etc)

[MITSIR]

thanks for that eastie.

I would have never thought of a better reason than that.

Will change the coolant to one brand. I do think that I have changed brands from the original coolant change.

[Eastie]

Although problems from mixing coolants is rare, it may have been the mix resulted in a less than optimal coolant blend.
Another option is do a pH test of the coolant (if it's ethylene glycol based) to see if it's turned acidic (pH <7). If you know someone with a fish tank they will likely have a simple and accuate pH test kit (cost about $10 from memory - fish shops would do it for a couple of bob). If this is the case the coolant has likely broken down into glycolic and formic acids which are not good for the cooling system in the long run.