Classic cars forum & vehicle restoration.

[Miken]

I learnt something today which you may already know. If you didn't, you are welcome.
2 years ago I filled up my cars cooling system with Bluecol 2 year antifreeze.
It's now time for a coolant change.
I have a 5 litre container full of leftover 50/50 antifreeze and water that I mixed up 2 years ago but haven't used.
I wasn't sure if this 2 year old mix would still be useable.
I contacted the manufacturer and it turns out it's ok to use.
Now you know.

[norustplease]

Good information.
It is probably the repeated heating and cooling in the engine wich degrades it whilst in use. I must admit that I have a couple of cans of antifreeze that are a couple of years old and I had wondered whether they were still usable.
_________________
1953 Citroen Traction
1964 Volvo PV544
1957 Austin A55 Mk 1
Boring Tucson SUV

[Kenham]

I may be totally wrong but I think this is a complete con changing the antifreeze every couple of years. I have machines that have had the same antifreeze in for 35 plus years and have never had any problems. What can degrade or is it the case the modern antifreeze is just not up to a good standard. My Defender 300tdi has had the same antifreeze for the last 10 years at least with no problems , I will stick with it being a con .

[Ray White]

[lowdrag]

I have never drained and changed the antifreeze, just drained a drop or two and added some neat to the radiator. But the car overheats in hot weahter and blows out half a litre when hot so all I am doing is replacing lost coolant. A never ending circle.

[MVPeters]

Keep in mind that anti-freeze also protects against corrosion. Prestone & others make very inexpensive 'turkey-baster' testers that will show the temperature to which protection is effective. eg: https://www.amazon.com/Prestone-AF-1420-Antifreeze-Coolant-Tester/dp/B000BOA9RY/ref=asc_df_B000BOA9RY/?tag=hyprod-20&linkCode=df0&hvadid=312151579877&hvpos=&hvnetw=g&hvrand=16666302657178098843&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9001901&hvtargid=pla-570724898553&th=1

My car is freeze-protected to -34F but the a/f is so old that I suspect the anti-corrosion protection is now minimal.
Coloring in a/f is largely cosmetic - there's no guarantee that blue a/f from one mfg will have the same chemical composition as blue a/f from another.
So rule 1 is 'never mix colors'. Modern engines have a wider variety of metals & plastics in them, so find the specs & capacity needed for your particular car. Then buy the concentrate - ready-to-use/diluted a/f is 50% very expensive cold water!
Dishwasher powder is an effective cleaner prior to a flush & change of a/f.
_________________
Mike - MVPeters at comcast.net
2002 MINI Cooper 'S'

[Ray White]

I think I will get one of those testers. Makes sense.

Interestingly, I learned something today; that pure antifreeze has a much higher freezing point than a 50/50 mix. Ethylene glycol freezes at 6 degrees F apparently.

(I am not too proud to admit when I didn't know something. I have a saying; "you don't know what you don't know")

[Miken]

When I rebuilt the engine 2 years ago I spent several days digging and clearing out all the hard rusty deposits that were obstructing the water gallery.
I was shocked at the amount of rubbish I removed. Areas that I thought we're solid metal turned out to be blockages and were hammered out using old screwdrivers and poked at with bits of welding wire.
This work would not have been possible with the engine in the car.
I put this down to years of previous owners not changing the coolant very often or at all.
This is why I've decided to keep to the manufacturer recommendations.
I'm less concerned about freezing.