2003 Audi A4 no heat problem.
 

Hey guys, new to this audi forum. My heat works great when it's like minus 5 to minus 10 and anything warmer. But the 2 times we have had cold snaps like now n early nov. i get no heat at all..I mean absolutely no heat. temp guage gets up to 90 when warmed up for about 20 to 25 mins, but no heat. I managed to flush the core back in october or november i can't recall exactly, but flushed it out and put new coolant in same time, made sure there was no air pockets in the system and it seemed to work, but now, back to square one. Any other suggestions that's not gonna cost me an arm and a leg to repair? lol. It's Gonna be minus 47 tonight SO tomorrow morning going to work won't be fun at all haha.

Re: 2003 Audi A4 no heat problem.
 

Hmmmm... I was having the same problem. Flushed out the heater core and I have heat. Today will be the first day since I had the heater core flushed that the temp will be minus 17 so we'll see how it goes.

Question guys, if you turn on your windshield defrost button (the one that makes your fan go to max no matter how cold the engine is) how long does it take the inside of YOUR car to warm up in minus 17 degree weather?

One thing you can check is the flap motor that allows coolant to flow into the HC. It might be sticky. I beleive a scan will give you that info.