Quote (ChowYunFat @ Mar 11 2019 10:22pm)

Cranking the heater and bleeding heat off the block seemed to help, but it would happen, regardless if the cabin was hot or cold.

Sooo... I've got it kind of fixed. The last part I threw at it was replacing the engine coolant temperature sensor. Replacing the ECT helped some, but didn't fix the problem outright.

HOWEVER!

If I bypass the radiator fan (via paperclip, so the fan is always on when the ignition is on), the car runs fine.

At this point, gonna call it "good enough", and I'll take it to someone with more experience than me when I get a chance.