u/Hauntingswan

So I currently have an issue with my tension on my machine. It keeps pulling up the bottom thread. No bunching, skipping, breaking thread. Just the machine pulling the bottom thread up a little bit. It doesn’t do it and I get a “perfect” stitch when the tension is at 0. Test have only been 2 denim layers. I’ve adjusted the bobbin case tension and it’s lose and it didn’t change anything. The top thread is at 0 and I’d like to readjust it so that it gives me the “perfect stitch” at tension 4-5.
Background of the machine:
Previous owners: Unknown
Maintenance frequency: unknown
It needs oil it shows signs of sitting in a garage collecting dust, gonna oil it soon.

https://preview.redd.it/kuef7eusve0h1.jpg?width=3024&format=pjpg&auto=webp&s=edab24347218ceac1eb3089b5dc92d9787cdc5d9

https://preview.redd.it/2jdzmm2tve0h1.jpg?width=3024&format=pjpg&auto=webp&s=a1735270d0945fad3c4dafd8db7fe2e04b79f709

So I was using my ender and it finally died. It started jamming every print now. Ive replaced the whole hot end and its still jamming in the heat sink and heartbreak area. I cant really see exactly where but that's where it lines up with. Would i need new fans since mine are pretty beat up (missing a blade, spinning slower, the side fan for the nozzle also isn't working at all). They haven't worked for a minute as their prime but the printer still printed. Ive replaced the hotend to trouble shoot and its having the same issue still so im guessing its the fans? Also if I replaced the fans first and it was still having this issue then it would just be the all metal hot end right? asking for another printer lol (i have a bigger printer with the same problem lol).