[m21sniper]

The block seal coolant system additive does work.

I can't tell you how many times i've used it on cheap-o cars over the years. As long as the leak isn't massive, it does actually work. You have to make sure you get every drop of anti-freeze out of the cooling system before you use the stuff though.

I know one person that got 4 years out of a car after using this stuff.