Both my 2005 elantra and my GFs 2005 elantra both have this issue. During idle when the car is fully warmed up, even when you stop at a stop light, the heat will cool down to where it will sometimes blow cool or cold air. Yesterday while I was driving with the engine warmed up, there was not warm air blowing at all only cold air. After messing with the controls I started getting warm air again but if I stop and the engine idles the warm air begins to cool down instantly.
I noticed the heater core hose IN was hot is normal and the output was cold. I don't believe the output should be cold correct?
---------- Post added 11-28-2010 at 05:53 PM ----------
Also I have been here many time before, Might know the name RotaMan. I am just having an issue logging into my original account.