ok i made a post last week about my heater not working but i have some updated news on it. i replaced me coolant temp sensor today cause my gauge didnt work either. well now my gauge works great but my heater still doesnt work. i have tried getting the air out of the system and it didnt help. everything seems to kick on like its supposed to, but the air that comes out just isnt hot. but now since i changed my temp sensor, my heater works a little bit. as soon as i turn the heater on it gets hot, but only for litereally 5 or 6 seconds and then it gets cold again. any idea's what could cause that? cause the fact that it gets hot for a few seconds means that everything is working right? but i dont get why it gets cold then after a little bit. any help at all??

 

If you have access to a vagcom check for codes in the HVAC system. Could be flap valve solenoid

 

I am still chasing this problem down as well. Replaced thermostat, flushed core/cooling system - works great for a day or so - then back to lukewarm air - if not almost cold at times. Right now it's in for a tranny, but I think the flap valve is the next area I need to look at. I've not seen a post here though where someone said replacing a flap motor solenoid cured the problem.

Also - I'm not sure my compressor is kicking in when I turn on demisters, not sure if this is related. Can someone comment?

Thanks;
Mike D.

 

how do you check for codes in just the HVAC system? i took it to autozone and had the diagnostics ran on it to see if i was throwing any codes and i'm not. is that the same thing? it just seems like everything is working good, i'm gettiing ample amounts of air wherever i want it, but its just not hot. its like ambient air from outside. but the heater hose's going into the firewall are hot so i know its getting heat in there somewhere. so how do i figure out where the heat is stopping? i've only owned this car 2 weeks and i have no idea where to start looking

 

No an OBD reader just reads engine and emission codes.