[SOLVED] Computer makes grinding noise on startup for 5 minutes, then behaves normally.

[lightningjaden]

Hi y'all!

My computer makes uncomfortable noises for about 5 minutes on startup: either near constant stuttering or rhythmic "turning over" sound (both recorded below).
https://voca.ro/1nk3NCmP808g
https://voca.ro/1kVmQKadEVCf


I've replaced the hard drive and the noise remains unchanged; taking off the side panels it sounds like the noise is coming from behind the brown CPU fan (holding the fan blades still on startup doesn't affect the noise.) Internal picture below, for what it's worth:

Touching the components, nothing seems to physically vibrate in time with the sound, and to my novice eye I don't notice any performance issues with my PC (my first build!). The noise never returns during long/intensive computer use: only startup. Any guesses or advice?

Thank you!!

 

[Cj-tech]

Hi y'all!

My computer makes uncomfortable noises for about 5 minutes on startup: either near constant stuttering or rhythmic "turning over" sound (both recorded below).
https://voca.ro/1nk3NCmP808g
https://voca.ro/1kVmQKadEVCf


I've replaced the hard drive and the noise remains unchanged; taking off the side panels it sounds like the noise is coming from behind the brown CPU fan (holding the fan blades still on startup doesn't affect the noise.) Internal picture below, for what it's worth:

Touching the components, nothing seems to physically vibrate in time with the sound, and to my novice eye I don't notice any performance issues with my PC (my first build!). The noise never returns during long/intensive computer use: only startup. Any guesses or advice?

Thank you!!

Have you tried unplugging the case fans one at a time to see if it’s one of them? Also, looks kinda dusty in there, might want to clean it out eventually.

 

[Rich-D]

I agree, it could be a faulty fan, but have you also checked to make sure no cables/wires are coming into contact with any fan blades. I've had that issue before and it sounded very similar to your recordings.

Could it be the cable connector that rests on top of the graphics card vibrating when the graphics card fans are spinning?

Hopefully it is not the PSU fan.

 

[Paperdoc]

What you describe sounds VERY much like an older fan with failing bearings. Identifying which fan will be important, and you started with the right idea, just never completed the search. With the case open and the system cold, get a pencil. Start your system so it is making noise. Use the pencil for each fan you have, reaching in to gently stop the fan with the rubber eraser, then let the fan run again. You will find the noisy one.

As a fan ages the bearings wear slowly, increasing the clearance between a motor shaft and the bearing sleeve. When this clearance gets too big the shaft "rattles around" in the sleeve and this happens most when the unit is cold. After start-up the friction heats up the bearings, and the shaft expands more than the sleeve so the clearance gets smaller, and the noise stops. It will stay quiet as long as the unit is still warm, but after a long shut-down the noise comes back during the warm-up time. Over time this period of start-up noise will get longer until it is permanent. Eventually the fan will seize up and fail completely, although this may take months to over a year. So, assuming you CAN identify that the noise IS caused in one fan by this type of bearing wear, plan to replace that fan sometime in the near-to-medium time frame.