I let BLUE run this morning for about 30 minutes before I headed into work to get her warmed up since temps have started dipping down into the 30's. When I got in, the heater was putting out cold air. Not outside temp air, but definitely not warm. So I droven down to the Speedway for my morning cappiciuno , which I might add is awesome! As I was driving the tempature got hot . Sticking to my old military motto, KISS, I am going to change the thermostat first. I alread checked the fluids and such too. No leaks or low fluids. So I am putting a new thermostat in tonight after work. My main question is, sound like a bad thermostat to you?

After a more thorough inspection, looks like a cracked radiator. Typical location too, top driver side.

Mine did the same..... I put a layer of Epoxy Fiberglass and more epoxy on it 3 months ago.... never had any problems again.