The Ethylene-Glycol based coolant becomes acidic with age. As it becomes more and more acidic it wil start to attack the metal components of the cooling system usually starting with the lesser noble elements like aluminum. It also becomes more conductive so it acts more and more like an electrolite conducting current, again attacking the less noble elements starting with aluminum. Go back to your High School chemistry, the Electromotive Series. Corrosion is basically an electric action except for fatigue corrosion. Anyway I don't believe it is the coolant's chemistry that destroys the Otterstadt, but it will attack the metals of the system. I lean towards Buce Benson's suggestion that once you overheat the system you probably damage the Otterstadt. But what came first? The bad otterstadt or the overheated system? If either can cause the other one then it is difficult to figure out which one died first. Bottom line, change the coolant (or at least test it) every 2 years and change the Otterstadt if you overheat the system. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, kjc <ckevinj@...> wrote: > > I remember a few years back that it was reported that old coolant would > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/