This is the first time my legacy has ever done this but here it is, my 2001 legacy started to overheat on me twice today, first time was going through the drive thru and it spiked up to 3/4 of the way then immediately went back to normal, after which I got on the highway traveled  75 miles, then had to go through a town with some stop and go traffic then it happened again. I have been noticing that the over flow tank has been filling up somewhat and today after these two occurrences it was over flowing. 

        What I was thinking is that it could be the radiator car is bad because it is the original one so I replaced it and haven't really drove it since. The head gaskets were done about 60K ago and the thermostat should be fail proof meaning that if it were to go bad it would stick open.

      I'm just looking for some input on this, like I said I may have fixed it with the new radiator cap but haven't really drove it yet. 

Edited June 11, 201312 yr by luko

well, the symptoms sorta mirror typical failed rad fan symptoms. But, soobs exhibit odd symptoms with bad head gaskets and after market t'stats.

 

If the t'stat BRAND/STYLE was the problem, I'd think you'd have had problems immediately - not 60K later.

 

check the fan operation first and watch for collapsing hoses - cros your fingers that the rad cap was bad but, seems unlikely.

 

hope it isn't HGs again.

If it runs normal temp on hwy, but only overheats when stuck in slow traffic........then it is your rad fan system.  Either the fans themselves, or a switch or wire, or the thermo failing.

Yep, I'd go with some sort of intermittent fan failure. Check your thermo switch first.

Nope, The both fans were operating properly. I did put a new radiator cap on it and topped off the coolant and it hasn't done it since!  

I think you may have fixed it with the new cap and top off my 95 legacy did the same think and I noticed my cap was not on properly once i sealed the cap and added some juice it was fine