Continued overheating in subaru

I have had the headgaskets replaced less than 10K miles ago on outback (overheating, smell of coolant, white smoke) and now that the outside temperature is increasing, my car is beginning to overheat again. in the winter, i had no problems with overheating, but with the summer temperatures, my temp gauge consistently reaches the 3/4 mark. i live in AZ and temp gauge problems only happens at 105+ outside temps and typically just when i’ve been going uphill.

is there a problem with the head gaskets again, or is it something else? Is this just a symptom of extreme outside temps or something I should be concerned about?

Please give me some good news! This car has been one ridiculous problem after the next and I"m so ready to junk it!

I forgot to mention that my outback is a 2000 and the mileage is now 145K

3/4 is higher than normal, but not necessarily “overheating” considering the circumstances.

I’m assuming a new thermostat, water pump, and radiator cap were installed along with the new head gaskets. That would have been the time to do it. If they weren’t replaced . . .

Do the fans work correctly? Is the radiator clean?

If the gauge goes back to normal when you’re not going uphill in 105 degree temperatures there may be nothing wrong.

I’m with McP on this. In temperatures that high and under the additional load of an uphill climb I wouldn’t consider the engine running hotter than normal an indication of a problem, as long as it doesn’t hit red and comes back down when the load is again reduced.

Remember that once the engine hits running temp and the T-stat opens, how cool it stays will be dependent on only the radiator’s ability to dissipate heat, and that engine has to work to get that vehicle up a hill. The air itself being over 105F affects how much geat gets dissipated. Hot air doesn’t pull the heat out of the radiator (and the coolant in it) as well as cooler air does.

And it’s a pretty safe bet the AC is running full tilt, adding to the load and dumping more heat right in front of the radiator.

Excellent point.

thermostat & water pump are new, not sure about radiator cap. why would this need to be replaced - is this what, as moutainbike says below, allows the radiator to dissipate heat? fans are fine but will have the radiator checked for cleanliness.