A friend here at work says that his buddy at Chrysler says that antifreeze will go bad when it is overheated. Specifically he says that one of 3 things will happen. It ruins your engine, it ruins your water pump, or nothing. Apparently your antifreeze becomes abrasive. I think he is referring to the long life coolant (the orange stuff)

I've never heard this.

Has anyone else?

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
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'85 300SD - 317,000 miles (sold)
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'83 Harley Davidson FLTC (Broken again) :-(
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i have not heard that, but when you overheat the extra heat loostens up scale and suspends it in the water. if you dont give it a good flush this loostened stuff may plug your rad and heater coils. so if it was overheated on that basis alone, i would clean it out and replace.

the other may be true too, i just never heard it before.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

as "outside designed chemical specifications." MB specifies theirs or Zerex G-05.

Chemical buffers and lack of phosphoric acid are good enough reason why for me.

Outside spec. (also consider WHAT HAPPENED WHEN IT OVERTEMPS, coolant too low = steam in upper end.) Not to lecture on it all but reactions happen in the big steam pocket that would not in fluid. End result is ceramic formation, blocking heat transfer to the fluid. This can be seen in radiators with six figures of miles on them which loose the ability to cool.

Add to that the loose 'stuff' that wasn't, AND the thermostat's internal wax pellet that is now distorted and should be R&R'd.

Bottom line - if you got toward hot check it with some test strips, if you boil over you have some work to do.
***NB, If you want longevity? - When you mix to refill, use DISTILLED water (not purified or filtered) you DO NOT want to add minerals back that were taken out of the coolant.

yes, and no

anti freeze is made of glycoalchol.

whiskey is made by boiling mash (mash is water and alchol) alchol boils at a lower point then water so the vapors are caught coming off the still and that is how whiskey is made.

So if you boil your coolant the alchol from the glyco will turn to steam and evaporate out of your system...and that can lower the effectiveness of your coolant to prevent freezeing...

they make a little tester that has little colored balls in it... very inexpensive. you suck up some coolant and the number of balls either sink or float showing how much alchol is remaining in your coolant... you simply ad more if needed.

So if you over heat to a boiling point you would use this instrument and you might have to add a quart of antifreeze... or maybe not...