I recently purchased a '02 legacy outback 3.0, 150,000 miles. We replaced the radiator because of a leak, thermostat & air filter. Originally I had to put the temp up to 80 to get heat in the car, after a time I could turn it down but again would have to turn it up to get heat as it would start to blow cooler air after a time. Since the work was done it had been better but again is starting to act up, I have turn the temp up to 85, back down to 72-74 but after a time will blow cool air & has difficulty warming up again. The engine temp has been fine, coolant levels have been fine since the radiator was replaced, tho I haven't checked recently. Thoughts?