No heat!

[forgetaboudit]

Hey gang, just bought an 04 9-5 ARC yesterday with 140k miles.
Drove it home about 40 miles yesterday and noticed the heat wasn't the greatest. I got home, had to resolder the headlight cube relay contacts and some other random things.
That takes us to today. I had to put a new battery in it as I'm guessing the car has sat for quite a while. Now with the heat on full blast, it's cold. I did the recalibration of the HVAC system after the new battery, I replaced the coolant temp sensor and thermostat today, and the heat is nonexistent. The temp gauge is right smack dab in the middle, and sometimes a little less than halfway.
My scanner shows the coolant temp is 185°F (put a 180° thermostat in).
I'm leaning towards it being a blocked heater core? Is that correct? Will a coolant flush resolve my issue? New core? PLEASE HELP! It's 10°F here and no heat sucks!

[nordwulf]

You performed all the steps and replaced items we usually suggest. You mentioned you calibrated the ACC system but didn't mention if there were any error codes showing?

[MikeB63]

Interesting. I am having very similar issues. I changed the coolant sensor and plan on changing the thermostat. My gauge reads about the same as yours, but at times dips to 1/4 or lower. I also was going to replace the by-pass valve thinking that it may not be operating correctly. I sometimes have heat and sometimes don't. Sometimes I drive a 1/2 hr into work with no heat and when I go home, it works fine. As for the heater core, can you check the inlet and outlet temps to see if one side is hot and the other cooler or cold?