Thanks for the link. Very informative thread.

My creak is different from the noise I heard on the posted video. Mine is more like a rusty hinge.

My present working theories are 1) the sound of PLA rubbing against the plastic extruder body below the hobbed bolt, and/or 2) the sound of plastic-on-plastic gears.

I am using 3mm filament. In hindsight I wish I had drilled out the extruder body. The print that came with my kit needed some cleanup in most places. But I failed to test fit the filament path.

I'll also mention that I get a lot of white powder (my extruder is white) on the x-axis V-rails. There is a lot of wear going on with the large gear, and perhaps the small gear as well. This explanation for the creaking doesn't seem to explain more noise with PLA than ABS, unless PLA requires more extrusion effort?

Jim