So on a 50 mile trip the other day, I heard gushing when I pulled into my destination. Coolant was pouring out from the lower heater hose. I could see the drips leading up to where I parked but it seems it REALLY let loose when I turned the car off. So I change the hose, top it off with only about a cup of water (seemed like there was more than that on the ground) and off I go. Now the temp gauge likes to "hunt" around the center mark on the temp gauge which it didn't do before. I would know, I look at the temp gauge more than I do the road. 

 

I drive it all the way home while it's "hunting", and today it was having an even harder time staying cool while sitting still than it did before. The radiator fans can barely keep it touching the center mark. So I park it on a steep hill when I get home, remove the cap and let it run. The temp does the same thing, hunts a little then sits slightly above the halfway mark and the fans are going full blast. But NO bubbles. So I'm guessing that there's air trapped in the heater core. How are you supposed to burp an EA81? I never really had any trouble with EA82s and from what I've read I shouldn't be having any trouble at all burping this thing. What gives? Maybe this unusually warm weather has something to do with it? Maybe the water pump is weak? Certain it didn't overheat on my trip, at least according to the gauge it didn't.

Check/replace your thermostat, it sounds as if it may possibly be partially stuck. boil a pot of water on the stove, drop the thermostat in, and see if it opens.  I believe it should open at 185* but am not 100% certain.

It does sound like you have a faulty t-stat.

 

Replace that, then do the following:

 

 

With the engine cold and off, remove radiator cap Top off fluid if low.

 

Start car and turn heater temp control to HOT.

 

Then watch the fluid in the radiator filler neck,  As the engine gets up to temp idling, the coolant should RISE, overflow a bit, then drop a ways. 

 

When it drops, top off the coolant, and replace the radiator cap.

 

Good to go.

It's a Subaru thermostat and it's less than a year old, so I'll throw the old one in and see what happens.