my 99 Legacy GT has been overheating, but we can't find any sign of a coolant leak.
the first time it happened I was ~3 hours out of town. We checked the coolant tank and it was full. we used some coolant leak sealer and put more coolant in, and were able to drive back home without any major problems.
this past weekend we went out of town again and at about 3 hrs of driving, the same thing happened. coolant levels looked ok but we added more coolant and the temperature gauge was stable and were able to drive back home.
could this be related to the head gasket? I just brought it into my Subaru garage but I want to have a better understanding of what might be the problem.