I am new to subaru's but not mechanical work. my question is if the thermostat is on the bottom does the flow of coolant go out of the engine through the bottom hose? And through pressurization recirculate back to the engine by way of the top hose. I am trying to figure out if water pump is bad or if I am air locked.

Edited August 12, 200916 yr by AS4MAN

these engines are notorious for getting air bubbles and overheating. was the system low, loosing coolant, or recently worked on - is that why it might have air lock?

 

if you just fill up the radiator or cooling system, they often overheat. have to get the air out.

 

lots of information on here about how to properly bleed the coolant, affectionately called "burping".