I was printing a benchy on my monoprice select miniwitha a e3d v6 nockoff and I saw plastic ozzing around my hotend
Remove the rubber boot. Is it clean or covered in filament? My guess is, as others have said, the nozzle is loose. It should not be snug against the block but against the other feed pipe. If filament oozes out the sides of the threads, it might get pushed around the inside of the boot and come out the holes in the top.
It was likely a loose nozzle that wasn’t properly heat tightened.
For those who don’t know, after screwing the nozzle in cold, crank the hotend up to max (or hotter than you ever plan to print by about 10C) and tighten the nozzle again. The thermal expansion is different between an aluminum heat block and a brass nozzle. The extra tightening while hot can overcome this problem.
In my experience the issue is more commonly because the heat break is not threaded into the block far enough to begin with. What then happens is the nozzle bottoms out on the block before making contact with the heat break. You should think of the block as more of a coupler, and want the heat break and nozzle to press into each other within the block.
That is true, without a doubt. What I am saying is in addition to that.
Aluminum will expand more than brass when heated. There will be a gap created between the nozzle and the heat break when heat is applied. The block is a coupler, yes, but it is also a shrink fitting by default.
Thermal expansion is fun. ;)
