I admit I don't do much work on VWs, but that seems to be changing quite a bit as of late. And of course, I'm getting cooling system jobs now.

Volkswagen specifies the use of G12 coolant and only G12 coolant in their automobiles, and it seems to be the general consensus of a lot of the morons on internet boards that everything's fucked within minutes of putting something else in, including the "universal" coolants and DexCool.

From what I understand, G12 (and G12+) contain organic acid corrosion inhibitors. And for those of us in the know, so does DexCool. As a matter of fact, I found documentation from Havoline that states that its DexCool coolant meets VW/Audi G12 specifications.

But, alas...I don't have much anecdotal evidence to back any of this, so I'm asking some of you your opinions. What say ye, brethren?

12/3/2011 8:16:04 PM

Real Volkswagens don't use coolants.

12/3/2011 8:32:39 PM

True. But I get more and more requests to work on the jizzwaterpumper variety. I need to know this so I don't end up with a precipitate/gel problem.

12/3/2011 8:43:19 PM

they sell pentosin at advance now

12/3/2011 9:19:00 PM

I know but the one on Western was out of stock and I didn't have the moneys to buy it if they had it.

12/3/2011 9:55:07 PM

If whatever job you're doing involves a full coolant flush the full strength G12 is sold at dealerships for just about 5 to 10 bucks more per gallon compared to the auto part stuff. If you're topping off what's already in there and the owner doesn't want a flush I go with the flow and put in what's closest to already there; if its any random color other than bright pink, orange, green its safe to say it doesn't matter (usually when its muddy or dirty brown) and the system is already on its way out. If you put in what is supposed to be in there (G12) and mix it with non G12 coolant then you're looking at possible precipitants and clogging/system failure. Tap water and hard water may not be pure enough and the inherent minerals exacerbate the precipitation effects. That's just my 2 cents and what I've done through the years.

It's the simplified version for practical purposes no doubt, you could go on and on about subjective scenarios from random people since there's no other real consumer level data to analyze to see the effects of mixing coolant types and contact between different materials and alloys. If anyone had that it would be a gold mine to quell all those forums dedicated to coolant types.

[Edited on December 4, 2011 at 12:41 AM. Reason : .]

12/4/2011 12:20:30 AM

on somebody else's car I would go with the VW recommended coolant. Perhaps beethead will chime in given his VW expertise.

12/4/2011 12:31:17 AM

put the correct shit in there and pass the cost onto the customer.

12/4/2011 7:51:43 AM

^ but who is to say what the customer has in there already.

12/4/2011 10:50:29 AM

So I spent a good amount of time reading up on traditional silicate/phosphate, organic acid technology (OAT), and hybrid organic acid technology (HOAT) coolants. Some pretty interesting stuff that explains a few phenomena that I've encountered over the years. The "mud" that so many DexCool users have complained about results from air entrained in the coolant...it's primarily sediment that results from local corrosion in areas that are not continually wetted.

Another phenomenon that so many of us have seen over the years is failure of plastic parts in systems...and this can be attributed to one of the organic acids in OAT coolants, which actually has solvent qualities. It eventually plasticizes, or softens plastics with which it is in constant contact. Honda and Toyota both refuse to use this inhibitor (which I'll have to go back and find the name; I'm currently on my non-multitask-POS non-smart phone) for this very reason, and their coolant formulations directly reflect this. Just about all other OAT formulations on the market, including VW G12, G12+, and G12++, do however.

SAE has a paper published on OAT and HOAT corrosion inhibitors, and I'll be buying it as soon as I get some disposable funds.

12/4/2011 1:54:22 PM

Quote :

"So I spent a good amount of time reading up on "

and that there is your problem Dan... get back to work!

12/4/2011 4:37:06 PM

Quote :

"Another phenomenon that so many of us have seen over the years is failure of plastic parts in systems...and this can be attributed to one of the organic acids in OAT coolants, which actually has solvent qualities. It eventually plasticizes, or softens plastics with which it is in constant contact. ... Just about all other OAT formulations on the market, including VW G12, G12+, and G12++, do however. "

interesting. i guess that may be the reason there are so many failures of plastic coolant flanges on the newer VWs (that use g12).

fwiw, we keep g12 and g12++ in stock. i've been trying to get a 55-gal drum of the ++, but nobody seems to be able to source it, not even the dealer (i have the part number for it, but it is not available)

[Edited on December 13, 2011 at 6:00 PM. Reason : .]

12/13/2011 6:00:20 PM

Quote :

"So I spent a good amount of time reading up on traditional silicate/phosphate, organic acid technology (OAT), and hybrid organic acid technology (HOAT) coolants. Some pretty interesting stuff that explains a few phenomena that I've encountered over the years. The "mud" that so many DexCool users have complained about results from air entrained in the coolant...it's primarily sediment that results from local corrosion in areas that are not continually wetted. Another phenomenon that so many of us have seen over the years is failure of plastic parts in systems...and this can be attributed to one of the organic acids in OAT coolants, which actually has solvent qualities. It eventually plasticizes, or softens plastics with which it is in constant contact. Honda and Toyota both refuse to use this inhibitor (which I'll have to go back and find the name; I'm currently on my non-multitask-POS non-smart phone) for this very reason, and their coolant formulations directly reflect this. Just about all other OAT formulations on the market, including VW G12, G12+, and G12++, do however."

Solution: A cheap bottle of prestone and a box of red RIT dye. I call it G12+++.

Actually I think those eurofags dye it purple now. I, too, have watched VW's crumble before my very eyes as all those expensive plastic coolant lines rot from the inside out. Horrible cars. I hate to even touch them because some bullshit plastic bit is going to break and cost more than I charge for the entire job.

[Edited on December 13, 2011 at 7:20 PM. Reason : .]

12/13/2011 7:11:32 PM

Well, there are further implications. Take a look at Ford plastic intake problems on the 4.6. How about the Buick 3800 intake problems? Intake gaskets on Chevy Vortec engines?

The biggest plus to the OAT coolants is that they provide corrosion protection for up to 150k miles. However, it takes a while for corrosion inhibition to actually reach its fullest...like a couple of thousand miles.

The older conventional silicate/phosphate inhibitor based antifreeze provides INSTANT corrosion protection across the widest range of metals...but is usually limited to about 30k miles, or 2 years. Manufacturers are specifying that coolants must not contain any significant amounts of silicates or phosphates, however. The precipitated sediment that often forms with silicate coolants is abrasive and often erodes critical areas in the thinner castings and plastic water pump impellers. And of course, phosphates are being targeted as emissions hazards, as they can render catalytic converters useless if exhausted, and they can create problems as runoff into our waterways and wetlands.

12/13/2011 11:15:03 PM