My PC is only about two months old and has a constant mechanical scraping or grinding sound, roughly like "szrr... szzz... rrr." I initially suspected the used graphics card, but the noise continues even when its fans are completely stopped. Changing the speed of the Arctic P12 case fans, Endorfy Navis F280 radiator fans, AIO pump, and Corsair RM850X PSU fan does not noticeably change the sound. The system has no hard drives, only NVMe SSDs, and the radiator is mounted at the top of the case. What other component could produce this noise? Could the pump still be responsible, or might it be VRM coil whine or another mechanical issue?
2 Answers
The sound is probably still coming from a fan or pump, even if changing the speed did not affect it. A worn bearing or slight mechanical contact can produce a fairly consistent noise across a wide speed range. Stop each fan and the pump individually for a few seconds—not all at once—and listen after each change. You can briefly stop a case or radiator fan by carefully holding the hub, but do not obstruct the PSU fan or touch any exposed components. If the noise disappears when one device stops, you have found the source.
Coil whine usually sounds more like a high-pitched buzz, squeal, or electrical chirp and often changes with GPU load or frame rate. A rough, intermittent scraping sound points more toward a fan bearing, pump bearing, cable brushing a blade, or a loose mounting point. Check that no cable is touching a fan and briefly test with the side panel open to help locate the exact area.

That makes sense. I only changed their speeds together through the BIOS, so I’ll isolate each one separately rather than assuming the speed change ruled them out.