My 91 LeBaron can't keep the heat going. It seems like the heater core keeps getting blocked. You can't even blow through it. If you backflush it then the heat is good for a while until the core seems to block again. The radiator was blocked solid and a radiator shop cleaned it out and it flows like new now. The coolant looks like it just got poured out of the container, but the heater core keeps blocking up. Could the problem actually be in the heater control valve? Could it be sticking closed? I looked it up on Rock Auto and they are cheap. They also list a heater core temp sensor. Any idea what this is and what it does? Where is it located? Any help or ideas would be appreciated.
Thanks,
Frank