Plastic start to ooze heavily when heating up.

I have a strange problem that I dont have even on my bowden delta. On my FLSUN i3 Plus I installed E3D V6 clone and extruder directly above it, so direct extrusion. But when I heat nozzle up to about 190C plastic starts to ooze out and wont stop for minutes. Even if I retract 3-4 mm there is still plastic coming out. I have checked, upper part of V6 print head, radiator, is room temperature to tuch, I have 40x40x20 fan blowing on it.Heat break and nozzle are tightly screwed. What can cause it?

Is there a gap between heaterblock and heatsink?

Yes, about 2 mm gap.

He means is the plastic oozing out of the nozzle or from between the nozzle and the heat block.

which thermistor been selected in F/ware.

No, plastic is going out from nozzle hole, from where it should. But too much. On my delta when nozzle is heated up there is about an inch of plastic going out due to gravity and ect, but here it just goes and goes for 5-7 inches. I checked temperature using water (dont have ir heat gun), it boils off is I tuch heater block with wet brush at 100-105 degree set.