Heat problem, help please.
 

Hey guys. I own a 2005 8, and the heating doesnt seem to work. Ive read a couple posts on the club about heating problems and it says to check if the knob is back by pressing the radio power button and the scan up button and see if the heat temp changes. i have done so and the temp does change. i feel like it might be a valve thing, but i dont know because im not that mechanically inclined. when the car is warmed up and i turn the knob all the way to hot and then blast it, there is a short puff of hot air that i would expect and then it goes back to cold. again new to my 8 so anything would probably help. thanks guys.

Did you leave the 0-16 display on while you used it?
The knob can change the #s, but it can change on it's own also.

Yes I did. The temp goes to 16 and hot air comes out for about a second and then works its way back to Cold air while the the knob is still on hot.

Ok, to be clear, the screen displays 16 the whole time when it starts blowing cold, and stays on 16 while blowing cold?
The knob can be on hot, and the display can go to 0 by itself and start blowing cold air with the knob still on hot.

Yes the display stays on 16 and blows cold.

Your heater core could be blocked or rusted.
You could try getting a coolant flush, especially if you don't know if it's ever been done.
The coolant could be weak and corroding the core.