Replaced G12 with Prestone AM/AM in an Audi A6

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Recently, I took on the project of fixing a coolant leak on the Audi A6 2.7t at the thermostat housing. It has the infamous plastic housing that likes to warp and crack eventually, so I "found" a nice metal housing on a core engine and replaced the plastic one with it and also the thermostat and seal. Topped it off with some fresh G12 and set out for the test run and to dispose of the old coolant.

By the time I reached the municipal station, everything was up to temp and working just fine. The attendant at the station looked under my car and said that there was a pond of some sort forming. Great, I figured that the seal on the metal housing let loose or something and I'd have to tear it all apart again.

Well, the spring clamp on the lower radiator hose failed and the hose popped off of the housing pouring all of my coolant in their parking lot.
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My arm was too fat to reach it to put it back on, so I filled up a couple of gallon jugs with water and headed back on the 3 mile journey to my home. Made it back to my garage with no problem, only having to stop once to fill with water to keep the temp in check.

One problem though, all the parts stores that I knew that carried G12 were closed on Sunday at this time. I headed off to Autozone and picked up Prestone AM/AM long life coolant, as it was the only one that stated it was silicate free in addition to being free of all of the other stuff that Euro coolant usually doesn't have.

Put in 1 liter of full strength to mix with the amount of water I thought was still in the system, and then added the 5 liters of 50/50 to get it up to the proper level. Also installed a new overflow tank as mine had seen better days. No problems so far and the heat works great. I actually prefer the neon green color of the Prestone to the pink of the old G12. Why they tinted any coolant pink is beyond me.

It's also nice to be able to pick up a gallon of concentrate for $14, as opposed to a 1.5 liter bottle of the G12 for $13.
 
There's been plenty of folks on Vortex or TDIClub loudly & proudly running Dex-Kool in VWs for years, your Prestone AMAM is likely just a green Dexclone.

I would not substitute Dex-anything for G12, but there's been enough cars out for long enough to say it probably won't cause any problems... but I also keep a gallon of G12 concentrate in my garage.

FWIW, all the stealerships near me charge $22/gallon of neat G12. No idea why yours are charging 50% more.
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Odd that you posted this right now. I was at the VW dealership 15 minutes ago picking up g12. A gallon was $26, which wasn't too bad compared to internet pricing.
 
Honestly, if it wouldn't have happened at a time where the parts stores that carried G12 were closed I would have replaced with G12 and called it a day. NAPA and Bumper to Bumper are the two in my area that carry Pentosin SF and they charge $12-14/1.5 liter.

Since my local dealer has even worse parts counter hours, I never even considered them for fluids.

At least now I can get coolant from any of the FLAPS and even Wally World if needed.
 
Makes total sense to run it now that you didn't have a choice, UNTIL you've gotten the entire thing 110% fixed and updated. Its cheaper protection and its already in there.

Once you've gotten it totally fixed, I might do a LOT of water flushes and then go back to the right stuff, which IIRC is better at passivating surfaces.
 
DexCool is similar to VW G12/G12+/G12++/G13. Both belong to the BASF Glysantin line but do have different formulation numbers.

I ran Motul Inugel Optimal Ultra in my S4, and the datasheet shows it as being acceptable for use in motors requiring DexCool.
 
You made the right choice.... Havoline Extended Life Anti-Freeze/Coolant DEX-COOL® is recommended for use in the
cooling systems of all types of automotive engines. This product meets ASTM D 3306 for
automotive service and ASTM D 4985 for heavy duty diesel service. It meets GM 6277M, Ford
WSS-M97B44-D, Volkswagen/Audi G-12, and most other European OEM specifications..... http://www.taligentx.com/passat/info/flu...lant.pdf....... a good read ....... http://www.motor.com/magazine/pdfs/082004_04.pdf
 
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