I know this one gets asked probably a few too many times but I'm now at the stage where I need to start considering this.
Printer: Ender 3 V2
Microswiss Hotend
Bowden tube setup
BL Touch
My stock hotend fan has a rattle, it does go away after a while if you give the case a flick with the finger but you can still feel the entire assembly has a chronic vibration.
My prints aern't affected by this, YET, but now is probably the time to start gathering idea's and parts.
I tend to print PLA, ABS, PC, and ASA inside an enclosure.