Depends on the circumstances surrounding your driving in the mountains...
- Which mountains and their location?
- What type of road you were on... interstate or winding switchback?
- Elevation you were driving at?
- What % grade was the ascent and the time or distance it took to get to the top?
- Your speed while ascending... slow or closer to highway speed?
- What was the outdoor air temp?
this trip is in az there are many grades as long as 3 miles and as steep as 8% the temp started out around 90 and ended up around 75 ..you start at sea level and 80 miles later you are around 7000 ft the road is a great 2 lane and it does a lot of winding streaches to its a 2 hr drive and I wasnt in a hurry so I babied it..I have a 05 liberty diesel no problems with the temp on it and have driven this route many many times...I was wondering if I might have a air lock coolant level was correct and the fan does run..open to any help