17 replies to this topic

[gazza82]

Don't think the block/head material matters as my Alfa uses blue (I mix 50/50 with de-ionised water) but our later MiTo uses red. Both have alloy engines.

[Dusky]

More information than you may want on antifreeze in the link below.
http://www.machinery...nt-fundamentals

Thanks. Read it, and (no pun intended) the article boils down to this:

Silicates (etc) are used as corrosion inhibitors.

Silicate are used because phosphate containing coolants don't work well with hard water. If you're uaing de-ionised / distiller water, I don't see why that should be an issue.

If you don't change your coolamt often enough, certain compounds in the "anti-freeze" can break down into acids. This in turn can start to corode your engine. (Acid + metal salts + ???)

There isn't any discussion in the article about engibes using components made of different metals : iron, aluminium, copper.

salts +h2 normaly. Wonder where it goes, should blow the rad cap

[fenghuang]

re metal + acid. Ah yes. It's 30yrs since I did chemistry.

Where does any gas go? The easy route out of the engine is out of the rad overflow.