I would have recommended replacing the thermostat before replacing the ECT. FYI, I recommend OE thermostats over aftermarket ones to ensure quality. Additionally, air in the cooling system is the most common cause of issues in my experience. Some vehicles are harder to get air out of than others. Yours may be one of those.
This may help with purging the air from the system.
Good hunting and please keep us updated.
- This reply was modified 11 months, 3 weeks ago by EricTheCarGuy.