i have a 97 a4 2.8 quattro. i have made several posts about my heater problems but something new has happened. today i was out running errands for awhile and decided to try my heater out to see if it would be warm at all. well i kicked it on high and it was hot as hell! but it only lasted like 2 or 3 minutes and then gradually cooled off and eventually became cold air again. any ideas what could be wrong? could this mean my heater core is partially clogged and needs flushed or what?? any other ideas what could cause this. could a thermostat cause that? cause in my experience, a sticking stat only causes the car to warm up to operating temp really slowly (and use alot of gas) or it sticks closed and the car overheats. could it cause my problem tho??

 

Could be a sticking thermostat

 

can someone please explain to me how a sticking thermostat can cause this? cause thats something new to me. if the stat was sticking and not letting coolant to get to the heater core and all that, then the car would be overheating...right? or am i wrong in thinking that? cause i can change my stat, but i just think it has nothing to do with the problem and if not, then i'm just waisting my time. any help??