Club 80-90 Forums

Hi all!,

If anyone can shed some light on this one, would be much appreciated as usual, thanks!

Had a look on wiki and some previous posts regarding VW G12 antifreeze and that generally it should be replaced every 2 years as a rule of thumb?!

Have 1Y 1.9 desiel engine on our van and the antifreeze is coming up to it's 3rd year of being in the system. Done a ph/test thing and it reads that the strenght is fine - only do about 3k miles a year, but don't know if that makes much difference to aging!?

Basically was wondering, although the strength reads ok, does that mean that the anti corrosion could still be going off though and therefore you should still replace despite strength reading fine? Know certain engines in our vans are prone to headbolts corrosion if not changed reg, but does that also apply to 1Y seat 1.9 desiel engine?

Any answers, much appreciated as usual folks!

Cheers all.

4

Dont worry about it if the strength is fine - in fact, you dont need to worry about the G12 stuff either - thats for petrol models which suffer from the corrosion issues i was led to believe....

Ringo

Interesting question...I have a few comments.
Firstly you are correct in your assumption that it is more critical to the wasserboxer engines but that certainly doesn't mean Diesels are exempt.
The low mileage since the last change DOES mean you are probably fine. Acidity increases due to many factors but these are mostly determined by engine cycles rather than time so although this is not an exacting science low mileage should mean additional year/years of coolant life although I'm sure you won't see this advice in any manual or factory service sheet.
At under 10K since the change I certainly wouldn't be worried.
ADDED DIRECT QUOTE from product sheet for a more thorough explaination:
Glycol in antifreeze breaks down over time to form glycolic acid (a weak acid) that reduces the pH of coolant and causes corrosion. Byproducts of combustion also contaminate coolant, causing further acidic degradation of coolant. At these lower pH levels, tiny rust particles begin to form, and combine with "silicates" in antifreeze and "hardness" in water to form insoluble gels.
Having read numerous articles, degradation of the antifreeze is bought about by many different factors, inhibitors breaking down, hard metal and combustion contaminination, electrochemical changes. Now I'm no scientist..I take these things as is and I certainly wouldn't presume to know everything, I am always happy to be proven wrong as this furthers my knowledge.
Martin

Red Westie wrote:Interesting question...I have a few comments.
Firstly you are correct in your assumption that it is more critical to the wasserboxer engines but that certainly doesn't mean Diesels are exempt.
The low mileage since the last change DOES mean you are probably fine. Acidity increases due to contamination from combustion gases over miles rather than time so although this is not an exacting science low mileage should mean additional years of coolant life although I'm sure you won't see this advice in any manual or factory service sheet.
At under 10K since the change I certainly wouldn't be worried.
Martin

I know I may sound picky but I can't at the moment work out how combustion gasses get into the coolant.
Cheers
Wolfie