I have a 2.5 L GT Subaru Legacy Outback. It runs fine but I have been having problems with it overheating. I have checked the oil and the levels haven't changed and also the coolant levels haven't changed. There are no drips or leaks under the car. The oil does not have any coolant in it and neither does the coolant have oil in it. I have replaced the thermostat and it still has the problem. It goes great up hill and on level ground; the thermometer stays just below level. Step down hill grades and idling has problems. Mostly when stopping abruptly and idling, it overheats.
Not sure what is wrong. Literally have no clue. I know car parts and such but not really the mechanics of the car. Can someone help?