Ender 3 Pro - Clogging nozzle and skipping extruder on second layer

[Bikeracer2020]

Did you heat the nozzle up to around 230 after loosening it and then tightened it up against the bowden tube whilst it was still hot?

[Gooz74]

Hi,

I finally found the issue and was able to fix it. It was very simple but I would never have thought about it.

After another couple of days searching I stumbled onto a You-tube video where somebody was explaining how to change a nozzle etc. and to the end of the video he mentioned that heat creep would also clog the nozzle.
Further he mentioned that heat creep could occur when the printer was in an enclosed environment or that the fan was failing and immediately I had to do a test.

For the last two years my Ender 3 was in an self made enclosure of Ikea Lack tables with Acrylic Glass walls. Until a few weeks ago, I never had an issue with that.
Therefor the first thing I did was open the doors and do a test print and what do you think? No more skipping extruder and no more clogging.

This morning I took the walls out of the enclosure, cleaned the fan completely (was almost clean) and the printer is printing all day now.
Thank you for all the help and helping me search for the issue. An issue that never was an issue but I learned a lot the last weeks.