Printrbot metal plus extrusion problem

This error usually happens after an hour to two hours of printing and takes at least a half an hour for it to stop, I've tried adjusting the pot settings but it did not fix it, nor does the motor feel hot/warm
https://www.youtube.com/watch?v=EWPV...ature=youtu.be

More probably it is a soft issue.

But anyway, have you checked the harness for chaffing and a damaged wire ? A damaged Z probe wire drove me nuts.