Rattling Noise in PC, Can't Find Source

[Addicted]

I recently built a new PC, and I paid good money to make sure it is silent at idle. However, it is making a rattling noise that sounds just like a mini idling diesel engine, and it seems to be coming from the front of the case.

What I have tried:

- Unplug the 2 case fans (one in front, one in back)
- Unplug CPU fan

- Remove graphics card
- Swap out PSU

 

None of these steps did anything to alleviate the rattling noise, and there are no other moving parts in the entire system. The noise is loud enough that it is annoying from a meter away, and I can hear it with my open-back headphones on. It sounds like it is coming from the front of the case right by the front intake fan, but unplugging that fan does nothing to stop the sound. Any ideas or suggestions would be greatly appreciated.

 Specs:
- MSI z170a SLI Plus motherboard
- EVGA GTX 1070 SC
- Corsair RM750 power supply (overkill, I know, but I got it on sale)
- Be Quiet! Dark Rock 3 CPU cooler w/ stock 135mm SilentWings PWM fan
- 2 140mm Be Quiet! SilentWings PWM case fans
- Enthoo Pro M case
- Samsung 850 EVO SSD (no HDD)

[Cyndre1033]

Maybe part of the case is clanging against another part due to vibrations/case is tapping part of desk? 

[tim19683]

are all the screws screwed in properely?

[tlink]

try fastening screws or pressing with your hand on certain points of the case gently (but still some force). it might be a cable or the case itself rattling.

[Addicted]

Thank you for all the responses! I tried what you've all suggested with no luck. However I completely removed both case fans and the sound disappeared. I replaced the rear exhaust fan with the one that came with the case, and the sound was still gone (but now with a higher pitched rattling from the fan). So either both Be Quiet! SilentWings fans are defective, or they are spinning at a frequency that is causing the case to vibrate. Either way, I've found the source of the issue. Thanks again for your suggestions!

EDIT: I just ran both of the fans out of the case, and they both make a very quiet rattling noise identical to the one I heard when they were in the case. So I guess the vibration traveled through the case, which acted like an echo chamber.