Hi my 2004 mitsubishi gallant overheated on big Bear Mountain this past Wednesday I have no idea why I drove the car for 2 hours and it overheated 20 minutes up the mountain at high 500 altitude the car has been driven to the Sierra mountains 8k altitude and back more than 4 times over a 12 hour drive no overheating issue I've had it checked out by a couple people but for now I have replaced the radiator cap because it was bad I have also bled the air out of my radiator because my heater wasn't working and now it is it it wasn't working the day it overheated You can give some tips on what you think it could be whether it a water pump coolant censor or thermostat or hose cetera The car has only started overheating this year Never overheats on the street even drove it to San Diego with no issue only in the high altitude doesn't make sense
