checking coolant by specific gravity?

Apr 06, 2015 3 Replies

I had a used engine fitted and the greasemonkey's invoice includes $100 for radiator coolant. But I think he has used the cheapest classic car coolant (no glycol) maybe even water with some green colouring in it. So if ethlyne glycol has SG 1.1 then a 33% mix should test as SG 1.033 Is this a valid check?


Depends on temperature. See chart at this website:

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all auto parts stores sell inexpensive coolant testers that will tell you what temperature you are good for. $4 and up.

If you use the little syphon with the coloured floating balls, make sure you tap it to knock the air bubbles off them. I once had a false reading that lead to "freeze plugs" popping out.

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