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This is what the workshop manual says for the 300 TDI:
CAUTION: Anti-freeze content must never be allowed to fall below 25% otherwise damage to the engine is liable to occur.
Also, anti-freeze content should not exceed 60% as this will greatly reduce the cooling effect of the coolant.
Remember that those who wrote the manual probably mainly want to cover themselves for conditions in UK and nearby European countries. I remember reading somewhere that 33% ethylene glycol will protect down to minus 18 degrees Celsius - presumably for a sustained period. Also, that in Australia, the only place where a lower temperature than this has ever been officially recorded in in the Snowy Mountains.
Re possible damage to motors from very low temperatures. In the very dry winter drought around here in 1982, there were many severe frosts but often relatively warm days. Note how moisture around provides a buffer against extreme temperatures. In those times, there was much less use of anti corrosion and anti freeze in radiators. There were a lot of cases in mornings of vehicles - which had most likely generally not been under cover overnight pulled up by side of road when they boiled - with steam coming out of radiator cap because the core below it was still frozen so no coolant could pass through it to be cooled.
Ethylene Glycol Heat-Transfer Fluid
Interesting point, and somewhat indicates that in Oz we should be mixing more like 33% not 50%.
Ethylene glycol - Wikipedia, the free encyclopedia
Also this wiki article notes that it does increase the boiling point of water, however it doesn't say by how much...
I'd expect even 33% to be excessive for all aussie conditions. But I accidentally bought same coolant from Repco that had very little glycol in it. It was essentially anti corrosive only.Quote:
Originally Posted by Judo
Bit of a trap as it was sold in a frosty area and looked like the real stuff.
Dropped by a radiator specialist today, he said no worries with glycol free coolant, it has all the properties it needs for corrosion etc, bar the glycol which is only needed to prevent freezing. He said it is far more efficient as a coolant which Im very interested in living in WA. He also said that glycol is really nasty stuff, poisonous in fact. Im always sus on trialling new stuff but I don't always trust the manufacturer's specs either. ATF in the gearbox is a good example of this.
I ran ATF in my R380 and it now has 470,000 trouble free K's on it,have run my Tdi on Glycol coolant for 470,000 K's and still have all the original cooling system fitted,if you want to risk your engine by not running what the designer of the engine recommends thats up to you. Pat
With anti-freeze the 33% ratio also means you have the correct dilution of anti corrosion additives, weaker that that and you might not get full corrosion protection.
I've used Castrol Anti-Freeze Anti-Boil at 33% since I got my 300Tdi (1998) with no issues. Changed every couple of years.
There were concerns a while back with some of the new long-life corrosion protection methods eg. OAT, HOAT etc. but these seem to have been overcome. I contacted some manufacturers regarding coolant for old Land Rovers a couple of years ago http://www.aulro.com/afvb/series-lan...r-engines.html
Ethylene Glycol is poisonous, as mentioned, and from memory outlawed in some Countries (France ?).
Colin
Propylene Glycol however is food grade.Quote:
Originally Posted by gromit
My advice would be as long as you don't drink it as your filling your radiator you'll be fine :angel:. PatQuote:
Originally Posted by gromit