Random hot-end temperature spikes I've been having issues with thermal runaways lately due to random temperature spikes on my Ender 3.
I figured it was out of calibration so I did a PID tune and still had issues. I then replaced the thermistor and I'm still having issues. I'm going to try replacing the heater element tonight.
However, if anyone has some suggestions, please let me know.
It looks like a sensor issue.  Maybe a temporary resistance in a contact of the sensor circuit made the temperature look low to the controler, so it applies power to raise the temperature.  When the contection recovers, the temperature is too high, so the controller lowers the power to restore the temperature.