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Altitude

I live at 6,000 feet. I drive my 1999 Jeep Cherokee 4.0 liter straight 6 everywhere. Last summer I was driving up to Silverton, Colorado @ 10,000 ft. I could not get my Jeep over 45 mph with it floored. The car overheated and vented coolant the entire climb - no AC going.



A couple days later I drove it at 8k & 6K feet at 85 mph, AC blasting for 2 hours straight and no problems.



I want to go back in a month. What can I do? No one can offer me any reasons

I don’t know about your Jeep, but most vehicles today have two electric cooling fans. One activates via a temperature sensor, the other is always on when the AC is on. It’s possible that if your Jeep is set up this way the regular cooling fan never came on and you were unable to sufficiently dissipate the heat, especially with the added load of climbing and the much thinner air. Air going through the radiator is where the heat goes, and much thinner air will not take it away as effectively.

In short, your temperature sensor operated fan may not be working and the fan for the AC may have done the job for it while you had it enegaged.

I do hope you’ve refilled your system…?