I just purchased a 69 Camaro that came with an Aluminum Radiator(don't know the brand, its not on it anywhere) and aluminum heads/intake. I was getting the car ready for winter storage and tested the coolant and it didn't go past 0 to -12 degrees F, which I thought was low. Problem is that the coolant is a transparent pink color. Does anyone know what kind of coolant this is? I am assuming that it is for compatibility with aluminum, bit i have never seen a coolant color like this. After some research, the only pink coolant I could find were from VW and Toyota. I don't see why they would have put these in there, so is there any other brands that are pink that i don't know of? If I should switch the coolant out to a different brand, which one(s) are best to use for the aluminum Rad./Heads?
Also, I saw someone mention on here that an open cooling system is not good for aluminum. Can someone explain why and is this only for certain coolants or all of them? My car has what looks like the cap that came with the radiator and an over flow hose that just runs to underneath the car. No overflow tank. Did these cars originally come with an overflow tank? thanks for the help.

There are industrial premixed coolants that are pink. Most mentionable is Ambitrol. It is extremely expensive, terribly vile stuff (and not glycol based) that is immune to everything that ruins conventional coolants. In the past few years I have seen some glycol based premixed pink.

I would drain it and flush it and fill it with green stuff.

The main thing that harms coolant is exposure to air and combustion byproducts. Both of these will rapidly deteriorate the additives and the PH will shoot acidic, where it is normally basic. The freeze/boil point is not what is altered by age/use.

A closed cooling system theoretically minimizes one of these gases. Theoretically:)

I used to use coolant test strips when I did maintenance. It is like a litmus paper that one side tells PH, the other freeze point.

sure it's not orange? a lot of the new long-life coolants are orange.

sure it's not orange? a lot of the new long-life coolants are orange.

Yeah, or red coolant in a very watered down state :).

thanks for the replies.

No it definitely not orange like in some GM's or red(my wife's CR-V has red coolant). it is like a transparent pink almost alittle more on the purple side in certain light then red. I have never seen this color coolant before and don't want to guess and mix something not compatible with it. I was hoping there was just another brand that i didn't know about. Problem is that I now have the car stored for the winter and I don't want to start the engine again till spring, so flushing the system out completely and changing the coolant won't work. I might just have to stick this one out this winter and hope that my garage doesn't get lower then 0 so nothing freezes!!! Then maybe I will change the whole system over to something like the Zerex G-05 stuff that i can get at the parts store thats supposibly safe for aluminum.

Anyone have any info on needing a closed system for aluminum part. Is there and truth to this or is it only for certain coolant? Anyone have aluminium parts with an open system(overflow tube just running to the ground) that hasn't had any problems?

The only thing that I can think of that is pink, is the RV type anti freeze for winter storage (keeps the water lines from freezing up). But I wouldn't use that in my car.

I thought the RV type stuff was orange. My wife's car was a toyota and it has the pink stuff. That would make sense. I would agree with flushing it and adding some new fluid anyway.

I have pink in mine also... got from work, from a 55 gallon drum. I'll try to get a name tomorrow.