Subaru overheating gremlins

So my Subaru Baja has had a weird cooling issue. It overheated (according to the gauge) and I had it towed. The shop has replaced the t-stat twice and has jacked around with it for a couple of days. This is not a Subaru shop- not one any where close by. I smell a very faint anti freeze smell and have watched the cooling level like a hawk. Doesn’t seem to be any major leak.

sound’s like a bad headgasket.