2.5 Engine was rebuilt about a month or so ago. Bought a factory t-stat and it was faulty. Forced to run without one for a few weeks and had no heat issues.

 

Got a new t-stat installed and it maintains temp at just under half local and in town. My issue is during my 45 min highway commute. The temp holds as usual until I stop at the light at the end of the off ramp and at any other light until I get to work. The needle rises to 3/4 or so until I am moving again, than back to normal.

 

I checked the fans and they are running as they should, no leaks and coolant levels are where they should be.

 

Ideas?

Any air bubbles in the overflow bottle?

 

HG leaks often don't show up until the engine is under load for a bit.

I'll have to check but I hope the hg's aren't an issue since I just changed them.

Are you sure the replacement stat is OEM, or aftermarket with a long coil spring? It is the cheapie stats with the short coil spring that don't work well on Subies, and cause over heating problems.

100% sure, ordered it from the dealer.