My 2001 Elantra GLS has developed a heat issue. The heat works fine, but when I stop at a light, the airflow gets considerably cooler. Once I start moving, it heats up again. Does this sound like a thermostat problem, or might there be another cause? It is so cold now here in Connecticut that I don't want to pull the thermo only to find it's not the cause. With no garage, I have to work outside.

 

[QUOTE=Stamford;47719]My 2001 Elantra GLS has developed a heat issue. The heat works fine, but when I stop at a light, the airflow gets considerably cooler. Once I start moving, it heats up again. Does this sound like a thermostat problem, or might there be another cause? It is so cold now here in Connecticut that I don't want to pull the thermo only to find it's not the cause. With no garage, I have to work outside.[/QUOTE


thermostat needs changed it’s either stuck open or half open

 

Sounds like good advice Josh !

Considering he asked this in 2014, probably a good chance it has been corrected by now .