Re: V8 Piston damage what do you think happened

Posted by Owen_Dyneto On 2009/4/2 9:53:04

so i wonder, since it is in antifreeze, why it is okay to use it in something with an aluminum block,

No, I didn't say it was in antifreeze (not as sold, at least), but that it's the result of breakdown (decomposition) of antifreeze. Or perhaps just due to the age of the antifreeze itself. Ethylene glycol which is the base of most permanent antifreeze is also quite corrosive to aluminum. The reason it can be used in aluminum engines is that it's formulated with "corrosion inhibitor" additives so that it doesn't attack aluminum. But although the ethylene glycol never looses it's freezing point depressing ability, the corrosion inhibitors are gradually consumed in the process of doing their job, leaving you ultimately (after ? years) with corrosive ethylene glycol.