I've been having a heating/cooling issue since I've bought this GS. When I got it, the AC/Heat wasn't blowing at all. I figured out the the blower motor control was bad so I replaced it. All vents blow nothing but cold air even when I have it in the 85 degree hot setting. I've read that it could possibly be a clogged heater core. If so, how do I flush it? Another possibility could be the temperature servo. I haven't done the auto-calibration to test it but do you believe it could be it?

Another thing, since I got the car, it has never reached normal operating temperature. It goes up a little but when I'm in motion it will drop to a real cool level. I parked it the other day and a stream of coolant was coming out of the coolant overflow tank.

Any suggestions on how to fix this?

 

Change the thermostat?

 

Yeah that's what I was thinking. I'm going to be doing a major tune up and that is on the list. I'm hoping the heater core isn't bad.