On my way to Vegas from salt lake I noticed my temp rising Everytime I was going up hill, but with my heater on full blast it's staying normal. So question is, cooling fans, thermostat, or temp sensor? Anyone have thoughts?

 

Could be one, could be all, could be none. Have you checked your coolant levels? You could be low and / or have air in your system.

Here is what I would do:

- Check your coolant level to ensure you have a sufficient amount

- Start the car, turn your AC on and verify that the fans power on once reaching operating temperature. The fans are programmed to power on low at 208*F and high at 212*F. If they do not, I'd then test the relay. Additionally, verify that your fans power on when your AC is on. If they do not, then disconnect the fans and test for power at the connector. If you have power then your fans are most likely bad. If you do not have power then work your way back and find the point where you no longer have power leading to the fans and begin there.

If the above are all within spec then move on to the thermostat. Depending on the year and mileage of your car then I'd consider just replacing it since you would already have it out.

 

It's an 04 with 65k. I checked fluid levels before I left and when I stopped to get fuel noticed fans were working properly. When I get to Vegas, I will change the t-stat and flush the cooling system.

 

Have you had the chance to look it over yet?

 

Not yet, got into town very late, going to look at it now.

 

Fixed, thermostat was stuck open. Replaced with a new one.