Filament extrusion stops suddenly during printing by PLA in DaVinci

I use a DaVinci 2.0 with repetier firmware with simplify 3D software.

During printing PLA aftere sometimes it just stops extruding the filament. At that time it sounds a bizarre "kot kot kot kot".

I even used a external fan to keep the extruder gear and the point where filament inserts cool enough. I tried to print from 190 to 240 C extruder temperature. Tried a variety of print speed settings. Nothing exactly improves the filament jam. Now what I do, is just pause the printing and taking the filament out, then break the filament head and re insert it again. It works for a while, than again it starts and filament stops extrusion.

Can anyone give a good solution what I may do?