01 Sebring LXI heater problem...

Hello there every1, Im having problems with the heater on my 01 sebring lxi sedan 2.7 v6. The vehicle takes forever to heat up, and once i start driving, the heater warms up, but if im stuck at a traffic light for awhile, the heater will cool down and start blowing cold, until i accelerate again.. What could be causing this??? any help would be appreciated. Thanks!

maybe you have a stuck open or leaking thermostat internally

Check your coolant level. Sounds like that is the problem. Speaking from experience!!!:lol2: