I have a 2001 Forester L, about 74,000 miles.

 

Last summer on a trip to Colorado and driving in temps approaching 100 degrees, my Forester temp gauge was repeatedly going to the three-quarter mark, at which time the A/C would stop blowing cool air. This would happen when I was driving more than 70 mph. Less than 70 mph, no problem with temp gauge or A/C.

 

During the trip, I brought it in to have the cooling system examined. They said everything looked fine.

 

After returning home, I didn't have any problems, but I was only driving around town and the outside temps never were extreme. No problems of any kind in the fall, winter and spring.

 

Today, with the temps more than 90, I took the Forester on the highway, with four people in the car and the A/C going. After about 15 minutes of 60 mph driving, the temp gauge went to the top, just below the red zone, and the A/C stopped blowing cool air. I turned off the A/C and drove home immediately. I checked the coolant level -- no problem.

 

So, any advice on what the problem might be?

i think you might have an air bubble in there. bleed the coolant system, and cross you fingers for the next thousand or so miles that you didnt blow a headgasket (improperly bleeding the coolant system can blow them, unlike the discussions on here about them blowing for little to no reason)

 

did you try turning off the a/c and starting the heat resolve the temp gauge?