What happens if I have two different kinds of antifreeze coolant in my Cadillac Catera?

  • 2
    What are the 2 coolants in your radiator?
    – tlhIngan
    Commented Jun 11, 2017 at 21:36
  • 2
    Can you clarify, did you mean "kinds" (as in difference chemical makeup) or did you mean "brands" (Prestone vs Peak)?
    – CharlieRB
    Commented Jun 12, 2017 at 13:29

1 Answer 1


If the coolants are compatible, they will mix and there shouldn't be any problems. However, if the two coolants are not compatible with each other, you will likely get nasty deposits. If there's enough of them, it may cause an obstruction and your engine will overheat.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .