While describing my problem of a broken, seized intake manifold bolt, and the different penetrating oils available on the market, as well as the "special sauce"(50/50 ATF & acetone), she asked, "So the corrosion is basically rust, right?"

I said yes, to which she replied, "Why not just use Coke?"

I didn't have an answer for her, aside from the fact that there's probably oil and other stuff in there, too.

Perhaps you folks,, who are exponentially smarter than me, have an answer.

 

I've used Coca Cola (regular, not diet) on corroded battery terminals and it did clean the corrosion off. If you could get it down the threads, it might work. I don't think the sugar in it will get down the threads to let the acid in it work. Personally, I like two products. Kroil which we use at work and PB Industries B'Laster Penetrant. It's some good stuff and you can get it at most auto parts stores. Depending on the manifold you're working on (aluminum or steel) you might want to heat it up before you spray it down. The gaps will expand making a better path for the penetrant.