just noticed last week my temp gauge got above half way this never happened before. so i changed the t-stat and still get hot. doesnt overheat but just hot 3/4 hot. seems to get hot when cruising low rpm and stop once i get rpms up it drops from 210 at stop to 190 when i get it 4000rpms. i did a flush got all the air out, the fan works. i dont know if it is a 2 speed or not. i am starting to think its the water pump but i only got 45000 miles. its 05 wrx. any sugestions vf39 ewg