paulpas

I don't want to hear "you gotta flush!" because I know that's not true and it's just fueled by the overcautiousness (perfectly cool with me but not this time). With that in mind, I have some low coolant. I used to have some Audi coolant that I had used and topped off with equal parts of distilled water. Alas, a hole was poked in that bottle and it is no longer an option as it it empty. It's memorial day tomorrow and I need to drive my car Tuesday so my options are limited. Do I just need G12 coolent to top er off? Any specific brand that you guys can think to avoid or look into? It's getting warmer, depending on how much I have to add (I haven't checked since it's not daylight yet) distilled water to tide me over since it wont freeze and I imagine (if like last time) I wont have to add more than 1/2 gallon to top er off. But at any rate, what are your suggestions other than the uber-safe-ultra-paranoid "flush the entire system!" since I am on a limited budget and I need to drive the car tomorrow.

Although the car just turned 100k miles, I may be due for a flush anyways...

turbo_flipper

if you're adding coolant that is...you don't need to flush unless you do what i did and add the wrong kind without thinking (but if you do, its about $80 out the door to get a full coolant flush...i hate my life sometimes)

otherwise, if you're just topping off, tap water should be fine. and actually, according to Audi, the Audi coolant is designed to never really need to be flushed. I don't know how exactly, something with the chemistry I believe, but my owners manual said something to that effect.

alpha helix

But remember that the boiling point will be reduced. You must restore the correct coolant mix with G12/distilled water as soon as you can.

Audi Junkie

I use Hybrid Organic Acid Technonogy coolant, Dexcool G-05 or "Mercedes" coolant, which requires a flush at changeover. G-12 is the biggest rip-off going, just use Generic Dexcool compatible unless you have 1996 model or earlier, then use G-11(blue) or Classic Prestone or be a man and flush it out...(Hint: G-05 is best).<ul><li><a href="http://www.motor.com/MAGAZINE/Articles/082004_04.html">http://www.motor.com/MAGAZINE/Articles/082004_04.html</a</li></ul>

PlainRuss

However I have made a nice killing replacing water pumps and over corroded coolant reservoirs on cars that don't stick with the G12. In the long run everything else starts crusting up something fierce and it ends up costing more in the long run. I'm sure you'll argue, and that's fine, but my daily real life experience says it's not a good idea.

Audi Junkie

and that's probally what you are seeing at work, the crust and blown seams and gaskets from Dexcool/OAT/G-12 in action. They are indeed the same formula: Dex is GM, G-12 is BASF. One substitutes potassium salts for sodium salts because of propritary reasons, their action is identical. Again, the recommended top-off by the Radiator Mfg Assoc for G-12 IS Dex and it IS the same formula and they are 110% compatible. Russ, if you want to do right by customers or friends, have them replace their G-12 with a lightly silicated Hybrid Organic Acid Technology and dodge that whole WP &amp; Radiator R&amp;R cycle. Direct comparisons of old Mercedes/G-05 and VW/G-12 cooling sytems at my BOSCH Service Center confirm HOATs' superior performance. I wish you could see the photos from the MOTOR Magazine article, look for last year's "Cooling" issue. I will even go as far as blame G-12 for blown Timing Belts due to seized WP. PS I suspect the new G-12+ has silicates.

PlainRuss

Any cars I see using anything other than G12 typically have the problems. The cars that have had nothing but G12 are typically fine. Granted, I used to read Motor magazine ALOT during my independant shop days but not so much since I am at a dealer. I would not say Motor has no clue by any means, but there is a world of difference between what factory tech's see day in and day out verses what a anyone will trying to collect data on a huge spectrum. I make zero money on parts, not here or at work. if you wanted to run Cambell's soup in your car verses what the manufacturer recomends, that's your deal. Unless your car is n my bay with my hands working on it, I have nothing to gain by giving you false information. I can only soeak from my real world experience as a professional, not an enthusiast as to what I have seen and what the consequences are. To me, saving a few bucks on Bob's coolant and tackle anti-freeze just isn't worth it.

Audi Junkie

Yep, Ford and GM are dropping OAT coolant for HOAT, like Chrysler uses, G-05. Wonder why?, G-12/OAT sucks. You statment sounds like dealer "lore" rather than real data. Here's what I would want to know, how do you determine what coolant cocktail a car you service has? Is this info reported by the owner? Did they mix highly silicated Olde Prestone, G-11, use hard water, air infiltration in the system? Are you sure your not just restating the old myth about mixing G-11 and G-12 causing a gelling effect? What protocol do you use to determine the contents of the system anyway? Coolant analysis is available, fyi. Fleet managers use it. I have a hard time with your statment about G-12 cars being fine too. What prompted you to open the system ...if it's "fine"?
Mine was not "fine", it had a blown rad at 85k, that's a disgrace, my '87 still has the original WP and rad at 200k. Any ideas? How about the plasticizer, 2-ETA? It's in G-12 and Dexcool. What do you think about the fact VW and Audi will be the only maker using OAT coolant? Will you still cling to your "statment" if G-12 Plus is a silicated Hybrid HOAT? Will you still use you G-12 OAT coolant? I already jumped ship, because I know the difference and have experience working with other cars that don't use OAT coolants, like Mercedes.<ul><li><a href="http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=forum&amp;f=37&amp;submit=Go">T ry your coolant stories on these guys.</a></li></ul>

TonyPNS

LOL...ole Bob has his hands in everything!

PlainRuss

Again I have nothing to gain by my statements. I don't make nor sell coolant of any kinda. I am a tech. I repair these cars. This is what I do for a living and not on the side. I have my hands on these cars 11 hours a day plus my own 2. I am not making this up. I have no idea why you would question my real world experience or professional knowledge and experience. But, again, it's your car, you can do what you want. I have never tried to steer anyone in the wrong direction on this or any other board nor do I intend to start doing so now.