The "blue" (cheapo) antifreeze is, I believe, an aqueous solution of ethylene glycol.

The "pink" (expensive) pukka stuff, according to the label, is ethanediol solution.

One hopes that both may contain traces of suitable corrosion inhibitors (...one hopes ...).

We are told that they must NEVER be mixed, ho no!, never the twain shall meet!

Riiight .....

Has anyone here tried mixing them (and lived to tell the tale)? What happened?

- it has been suggested in prior threads that they react to form much brown sludge, but ...

Ethylene glycol and ethanediol are the same compound! - just alternative names for the same stuff.

(I did check with the 'Rubber Bible', to make 100% sure).

So what goes on? Is there a real reason for keeping them apart - e.g. mysterious sludge - if so, precisely what reaction occurs? ... or is the pink "Long Life" stuff just a handy way of parting gullible fools like me from more of their money?

(Some more in this link, which I found interesting although too light on the science).

http://www.sancarlosradiator.com/antifreeze_coolant.htm

(Wiki is a bit more forthcoming chemistry wise ... but gives me the feeling that the manufacturers / Snake Oil salesmen are not as clever as they'd like to have us believe).

https://en.wikipedia.org/wiki/Antifreeze_(coolant)

BTW, I have a longstanding, persistent, very slight (i.e. not visible) loss of coolant from the Favorit. This annoys me, and I have toyed with the idea of bunging in some proprietary sealant. I am however reluctant to use that stuff when I don't know what it contains - is anyone out there into sealant formulations?

To me any 'sealant', 'additive', or other miracle 'just pour it in and live happy" solution fall into the same category: Bull$hit. A multibillion gray business as honorable as "food suppliments", "homeopathic medication", or whatever they are called. Don't bother. Nothing puts back worn material as nothing stops women skin from aging (yet they would smear any expensive goo on them). Presurize the system, find the leak, fix it.

 

As for coolant mixing, I don't bother with any 'bible'. Skoda recommends clearly what to use. I change coolant every 2 years. No need to mix if you fix. The leak.

Thanks, RicardoM. I share your views on BS wholeheartedly!

My OP was perhaps a bit ratty, because the pukka red stuff comes with a statement - unsubstantiated - "It offers significant benefits over traditional silicate based Antifreeze[sic]". That really annoys me, because IMHO that kind of thing is really very low-grade BS indeed ... heck, when I am paying top price for a so-called 'premium' product I expect, at the very least, seriously high-grade BS to accompany it ;-)

That said, I do not doubt that it may offer 'significant benefits' to those seeking to part us from our money! For that reason, I do not share your confidence in vendors' 'recommendations' unless they come with a plausible explanation (other than ripping off gullible customers, that is).

I agree with your suggestion about pressurising the system to identify a leak but the snag is that, with a hot engine, a tiny leak tends to evaporate faster than you can spot it .... I'm scratching my nether regions trying to think of a neat way of pressurising a cold cooling system to around 1.5 bar .... any standard solutions to that problem, or bright ideas, would be most welcome.

If no Briskodians can come up within the next few days with the Real Deal explanation as to why mixing blue and red antifreeze might result in Armageddon, then I propose ... in the interests of science ... to try boiling up samples of both together. (In that event, and if I survive the experiment, I might be able to add further to this thread).

For all things that don't make sense, smell bad, yet are wrapped in nice packages, humans invented the marketing. We know who works in that area, the master BSers. They sell using words like Ultra, Super, Premium, 30% Free, and my favorite "the NEW... X product"

 

Now about mixing coolants. Theory says that two different coolants are not compatible. The coolants chemically react and form a gel rather than a liquid. The coolant stops flowing through the system, clogs up coolant passageways and water jackets, radiators, and heater cores. The water pump overheats and fails due to a lack of lubricant in the coolant. Head gaskets blow, heads warp, and the engine suffers major damage. But even if you are sure that both coolants have the same formula I suggest you do a simple test. Mix in a pot small quantities of coolant, boil the mix and examine visually its properties. Compare to each unmixed sample.

 

About pressurising a cold cooling system to around 1.5 bar. You need to build an adapter that will replace the cap of the expansion reservoir. Fit a Schrader valve to adapter and use a foot pump for tyres (with manometer) to build pressure. Put white paper tissues in suspect areas to act as markers for leaks. For the rest of the cooling circuit (engine block), some older Felicias and probably all Favorits have a plug (a screw) in the engine block that you can use to make another similar addapter. If there is no such plug, at least you know the outer cooling circuit is good and by elimination you have to admit there is either

• a tiny crack in the engine head gasket or
• a tiny crack in the engine block or
• a tiny crack in the engine head

Edited 15 December, 201411 yr by RicardoM

Hello Skodle,

I would certainly be keen to learn the results of your blue/red mixing experiment. With all the mystery and folklore surrounding pink antifreeze, it'd be good to get an answer as to what actually happens when the irresistable force meets the immovable object! Maybe it will result in meltdown, maybe it won't.

 

I'm not quite an OAP, but I can't help thinking life was much simpler when all cars had blue antifreeze in the radiator, EP90 in the gearbox and 20W50 in the engine and that was all there was to it!

Why did it have to become so complicated?