[masraum]

Good luck.

As Scott experienced, with crazy high temps, things will be hotter and expand more. I've never driven at elevation, but it wouldn't surprise me to learn that an elevation change like that would have an impact on an automotive cooling system in perfect working order.

The boiling point of water @ sea level vs 9,000 feet changes from 212º to ~195-197º. 15º is a big change, and seems likely to change a cooling system.


Another factor that also probably has a huge impact is the change in atmospheric pressure. Atmospheric pressure at 600' is ~14.4psi (sea level is ~14.7). Atmospheric pressure at 9000' is ~10.8psi. So to get similar performance out of a radiator cap at that level, if the stock radiator cap is 15psi you'd probably need 19psi at 9000'.
https://esenssys.com/esssienew/wp-content/uploads/2021/02/altitude-vs-atmospheric-pressure.png.webp

I think this is probably "normal" for the drive that you performed. When you get back to SA, I suspect you're going to need to fill the radiator/overflow.