Weird issue with PLA printing

Can't print PLA.
I've printing a lot of ABS, usually with no problem.

Now I'm trying PLA. now, the thing is that I can extrude some. and as long as I keep pushing it (by hand, or extruder), it keeps going.
Once I stop, even for few seconds, when I try to extrude again, it will go for very short time and then get stuck.
Tried 195,200,205,210 and 215 degrees.
always with fan on.

Now, I printed PLA before with no problem.
Today I changed hotend to chinese E3D V6 (had it as spare part) because I broke my original lite6 hotend. So it might be the reason, something with gaps inside or something like that....chinese stuff.
BTW, it prints ABS just great.


Anyway, if anyone have any idea that might help, I'll be very thankful, cause I don't have time to wait until a new lite6 will arrive

if it helps, this is how the filament look after I take it out

Your hotend is assembled the wrong way. You have a gap between nozzle-collar and heatbrake.

I'm afraid you have to disassemble it completely and mount things in the right order:

• Screw the nozzle in the heaterblock completely and then turn back 1/2 turn
• Screw in the heatbarrier until it meets the nozzle
• Now screw the heatbarrier into the heatsink. Leave a gap between heaterblock and heatsink
• Now tighten the nozzle
• Install hotend in printer and insert heater element and thermistor

I swear i did those steps about 6 times :-/
only the heater and thermistor were already installed.

It looks like a gap, but I can't understand where.
The last time I assembled it, I tighten the nozzle at the end so hard that I broke it. Had to disassemble and assemble the whole thing again with new nozzle.


so...any ideas what is going on?

Does your heatbrake have a cavity for a short piece of PTFE? Is the PTE tube in there?
If not, that would explain the gap.