240 General: Blue antifreeze not blue any more

[Clifford Pope]

For years I have always used old fashioned ethylene glycol antifreeze, at approximately 33% concentration. This comes as a dark blue concentrate with corrosion inhibitor and I use it all the year round. Even after dilution it is still very definitely blue. One advantage is that any seepage shows up as a blue stain, and the level is instantly visible through the plastic reservoir.

Two months ago I replaced the radiator, flushed the block thoroughly, and refilled with my usual mixture. On the previous occasion, probably a week or so ago, when I checked the level it was up to the Max mark, and very visibly blue.

Today I have checked again. The level is still the same, but the coolant is now totally colourless.
How has it become bleached so suddenly?
Has the formulation been changed, to do this?
Does this indicate a sudden depletion of the coolant inhibitor, as a warning that something is wrong?

What on earth has happened? In over 50 years of using blue antifreeze I have never seen it lose its colour.

[cheshired5]

What brand did you use?

After flushing my system and using the very green genuine Volvo coolant, it's still very green 2 and a half years on.

[Stephen Edwin]

Originally Posted by Clifford Pope

For years I have always used old fashioned ethylene glycol antifreeze, at approximately 33% concentration. This comes as a dark blue concentrate with corrosion inhibitor and I use it all the year round. Even after dilution it is still very definitely blue. One advantage is that any seepage shows up as a blue stain, and the level is instantly visible through the plastic reservoir.

Two months ago I replaced the radiator, flushed the block thoroughly, and refilled with my usual mixture. On the previous occasion, probably a week or so ago, when I checked the level it was up to the Max mark, and very visibly blue.

Today I have checked again. The level is still the same, but the coolant is now totally colourless.
How has it become bleached so suddenly?
Has the formulation been changed, to do this?
Does this indicate a sudden depletion of the coolant inhibitor, as a warning that something is wrong?

What on earth has happened? In over 50 years of using blue antifreeze I have never seen it lose its colour.

Clifford, I'm sure you know better than I do, there are cheap little testers as to the strength of antifreeze in the cooling system. Very well worth using one I think as the colour has gone and it is winter.

As for the colour loss and the cause, that is quite a puzzle. One link by searching the interweb suggests a Fiat owner suffered loss of blue colour in the coolant and it indicated a head gasket leak.

[Clifford Pope]

Originally Posted by Stephen Edwin

Clifford, I'm sure you know better than I do, there are cheap little testers as to the strength of antifreeze in the cooling system. Very well worth using one I think as the colour has gone and it is winter.

As for the colour loss and the cause, that is quite a puzzle. One link by searching the interweb suggests a Fiat owner suffered loss of blue colour in the coolant and it indicated a head gasket leak.

It's still ethylene glycol - it smells the same, very very cautiously it tastes the same, and a sample doesn't freeze in the freezer.

The head gasket leak is a worrying possibility, although there are no other signs of it. No coolant loss, no bubbles in the expansion bottle, no overheating.

It's called "Silver Hook", for some peculiar reason. It's the stuff I've used for years, from the shop that used to sell Comma. Concentrated blue is very difficult to find now - Halfords only sell overpriced ready-mixed.

[timetrip]

Got some concentrated antifreeze from halfords {cannock west mids} but the pink version....

[Jungle_Jim]

Originally Posted by timetrip

Got some concentrated antifreeze from halfords {cannock west mids} but the pink version....

Be careful - you're not supposed to mix types of anti-freeze - there's two main types.

Glycol based - which is usually blue-green - that's OE for Volvo redblocks - and quite possibly what your car's currently got. If it looks like the current coolant in your car is blue/green (or was), then definitely take a step back before you start putting pink stuff in.

The other type is OAT (organic acid technology), which is often pink or orange (this is presumably what you've bought).

OAT lasts longer - apparently 5 years, where as Glycol is supposed to be 2 years.

They say that if the two are mixed, there can be a residue - particles or glug can form, potentially blocking the radiator.

Here's two threads discussing coolants in redblock motors.
https://www.volvoforums.org.uk/showt...t=Glycol+comma
https://www.volvoforums.org.uk/showt...88#post2148988

People recommend the Volvo-brand Glycol, and I emailed Volvo to find out the makeup of their coolant and it turned out to be BASF Glysantin G48 - which is available from other sellers including Comma.

Hope that helps
John

[Clifford Pope]

No, it's the traditional blue stuff I've always used, of the same make. It's just that the coolant from the new bottle has lost it's colour in about a week, whereas the old stayed blue indefinitely.

I've just conducted an experiment:

1) testing a sample of freshly-mixed coolant in a clear glass dish and adding a few drops of battery acid, to simulate corruption of the coolant with corrosive combustion products. No effect.

2) boiling the sample for several minutes, to see if heat was causing the colour to break down. No effect.

3) Bubbling exhaust gas through a freshly-mixed sample of coolant. No effect.


In each case I tried a far more concentrated dose of the suspected culprit than could possibly be present in the actual engine.
My conclusion is that whatever is happening is unlikely to be caused by anything adverse taking place in the engine, and must surely be more likely to be caused by some change in the coolant specification, causing the dye to be less stable than previously. It is I now realise a much less intense blue than I remember it being a few years ago. Perhaps it's caused by a change in EU regulations?

[Reg E]

I guess you have thought of this but maybe contact the manufacturer to see if they have any ideas?

I searched for ages to find blue antifreeze and purchased 20 litres when I found it in an old school ironmongers last year. I flushed and replaced the coolant in my two 50's Fords and it is still very blue when I checked them Monday this week as the weather had turned.

Not sure of the brand, I'll take a look tomorrow if I venture out to the cold, cold garage

[morsing]

Very oddly, the glycol based stuff they sell at Halfords is now pink. Does anyone know the reason for this?

[c1800]

Well, I’m across the pond, but your blue is the same as our green. i.e ethylene glycol coolant. While I’m not familiar with Halfords coolants, pink doesn’t sound right. I looked at their website and it’s not clear which coolant is which colour. Paramount is that you need ethylene glycol. You could ask them directly.