Mk3s extruder clicking  

Mk3s extruder clicking

I've only had the printer for a few months, and I've only done about a dozen prints so far, with no real problems (other than the normal first layer adhesion issues due to not being calibrated correctly the first time, and trying prints without adhesive goo).

Last night I printed my first higher-quality setting job and got what I'm now learning is the dreaded extruder clicking.  I had left the quality on draft (.3 layerheight) and had turned on variable layer ht and tagged a few layers that I wanted to look better.  I also turned on ironing.

When it got to that layer (about an hour into the print) it started doing a lot of clicking.  I didn't realize it was a problem until a few layers later when it became clear that no filament was coming out of the extruder.

It took a lot of futzing and such to get the filament unloaded, and then quite a bit to get it unjammed.  I used the needle and boosted the head temp up to 280 and finally got it unclogged.

Success?  Not so fast....

Now, I can't even get the filament auto-load feature to load the filament without the clicking as its trying to purge the old color.  The symptoms are kinda strange... the first few prompts of "has the new color showed up yet?" that I answer no to will kinda work with a lot of clicking, but after the first few, it completely jams and is 100% clicking.

So I took the extruder head apart and took the heat break out and inspected the PTFE tube.  The tube looks pretty good, nothing obvious.  I can see down the hot end and through the extruder tip and see daylight through it.  The walls of the path that I can see seem pretty clean, just a few specks of plastic or something.

Other than getting a new hotend that doesn't have the 2.2mm issue, what should I be looking at on the current one to just get it back to where it was initially?