Hey guys,
I am not getting much warm air in the cabin when I need heat. I researched online and the consensus was the heater core may be clogged. I flushed it out today and still no heat. The temp guage registers the same it has forever. Could the thermostat be stuck open? Wouldn’t that show in the temp guage? Also, can a bad thermostat cause the “check engine” light to come on? Any help greatly appreciated!
Rick

 

Try swapping the heater hoses attached to the firewall. If the core was clogged, that should back-flush it. You may need to flush the entire cooling system again, but swapping the hoses and solving the issue diagnoses the issue.

As for the CEL, you'll need a code reader.

 

Thanks. I did backflush the heater core with the garden hose. I was expecting more crud to come out but it didn’t. I have a code reader that says Lean on Banks 1&2. My local repair shop has done at least 4 different things to cure check engine light and finally gave up. I hate to take it to the dealer but I’m out of options. I have a new thermostat and gasket waiting for pickup. Hope it’s not too much hassle to swap it out. Anyway, I’ll try your tip. I think I want to put regular hose clamps on anyway (it has those squeeze type, PITA).

 

The core could be coated, not transferring the heat. OR, you might have a baffle door open, drawing outside air.

 

I guess I was a little premature in reporting that my core flush didn’t help, Today on the way home from work I turned on the heat and it’s pretty warm. Good enough for North Florida winter. Thanks for the advice though.