Heater core question

[cmo1234]

How does it work, I mean know the coolant runs through it to make it hot. But when put the climate control lever to "HOT" does just the air get diverted over it to blow warm meaning water is always circulating through it. Or when I turn it to hot does the water start flowing through it only then?

 

I'm asking cause mine is clogged somewhere and I'm getting no heat. So I'm gonna try backflushing it somehow to see if it gets cleared out but I dont want some valve somewhere closed preventing me from doing this. The car had a ton of stop leak poured in a long time ago and I think that is what is clogging it..

[Bizzo]

Your best bet is to just replace the heater core with a new one...they're not that expensive I had to replace one in my corsica i'm pretty sure it only cost like $45 and took about two hours to do. The worst part is contorting yourself to get under the dash to get it out.

[cmo1234]

Yeah I may have to end up replacing it anyway but I still wanted to know how it worked exactly

 

Is coolant always flowing through it and only air is diverted when you move the lever to hot or does the coolant only start flowing though it when you move it to hot...anyone..

Thanks

[SleeperRed90TGp]

Don't know lumina's very well but if it's a typical gm heating system yes the water flows through all the time. You can check this by feeling the lines by the firewall. They should both be the same temp. Next test. Motor off key on, move your heat/cool lever , knob what ever from one extream to the other. You should hear the air vent/duct motor running. I will run for 3 or 4 seconds when moved from hot to cold. If you don't hear the motor its either the motor or your heat/cool control.

 

I sure wouldn't chang that sob of a heater core unless I was positive it was plugged.

 

Hope this gets you warm.

 

Jud