have a quick question guys. my friend have a 99 a4 1.8t. and he was telling me that he put a prestone anti freeze coolant(yellow jug) in his car. is it safe to do that? even if the thing said on the jug is (can mix with any color of anti freeze)? what will happen if its not good? thanks guys, your help would be highly appreciated...what do he needs to do to change the coolant? does he have to drain it then replace the coolant?

 

When they say "any color" they mean any other color you can buy on the shelf. Audi OEM G12 coolant is a very specific coolant that when mixed with anything but G12 will cause lots of problems in the long run. It may run through there fine now, but after a while, it'll turn to a gel that will be a nightmare to get out of all the nooks and crannies. Tell your friend to get it replaced now while its still liquid. Changing it will require draining it all out, filling up the system with water, draining it again, filling it again, running it, draining it, and then filling with the proper G12.

 

I remember someone did testing on this. Like said, it will eventually turn into gel when mixed.

You might have to flushed the coolant reservoir.

 

and mixing colors is never suggested anyways, regardless if it says mixes with anything, stick with same brand and/or color

 

Yeah, I agree with the others. You can use it if you want, but don't mix it. One or the other.

 

C'mon guys... the only time it'll 'turn to gel' is if it have Silicates in it. The 'mix with any color' types are OAT and HOAT types that either have NO silicates (oat) or very, very little (hoat). Prestone is an OAT with no silicates.

G12, while different than most, is NOT 'very specific'. Its an OAT with no 2-EH (from BASF, Glysantin-30 and now -38). Prestone is OAT with 2-EH.

So, yes, you can mix them.

 

i would fill up my radiator with raw sewage before i put prestone in it. no you can not put generic green crap in, especially when mixed with G12. i was the one who did the antifreeze experiment a while ago. any of the samples with prestone in it had solids precipitate out of soloution, promoted decay of the metal substantially more then the others, and greatly increased electrical conductance. you can run something like dexcool (equally as expensive and hard to find usually) if you do a complete flush before. if you are dead set on using generic garbage coolant, it needs to be flushed every 2 years, and you need to flush the system completely with water before putting the cheap stuff in. or you can spend the few extra bucks and flush it with G12 and never have to worry about it for atleast 5 years other then topping it off with some water if the level drops.

 

I have no idea if running Dex-Cool is a good idea, but no, it's not hard to find. Autozone carries it.

 

i think your right...how do you know all this stuff??

 

Research..