I have a 15 with 36,040 miles on it and am pretttty sure the heater core is shot. I was eating lunch in my car with the AC blasting (5 minutes maybe) since it's 120* here in Arizona. All of a sudden the AC dropped temperature and I started to smell that dreaded sweet coolant smell coming through the vents. I made sure I wasn't leaking any coolant and after a minute or two the AC got cold again. It has been a couple days and every time i start the car, whether recirc is on or off, I get that nasty smell for about 5-10 minutes then the smell dissipates. Ford is going to look at it even though it's out of warranty because of a few "problems" I've had with this particular dealership thankfully, but wanted to see if anyone else had this issue and what Ford did in their case.