This question already has an answer here:

I did already some research but can't find anything in my pc or on the internet about my cause. Some fans in my pc are suddenly getting loud for like 10 sec and than going quite again for like 5 and this keeps going. Or the temperatures on my pc are okay, I have never overclocked my pc and the noise is there even without using the pc.

marked as duplicate by Ramhound, Ƭᴇcʜιᴇ007, mdpc, nc4pk, JakeGould Jan 6 '16 at 5:14

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • Bearings in the mechanical parts wearing out -- time to replace likely. Otherwise there may be a shroud around you can remove if it's off balance due to wore out bearings until your replacement arrives. Sometimes you can put some lubricant in the bearing parts of the fan after you remove it and have everything powered off for another TEMPORARY fix. The fans are critical to PCs as it needs air flow for cooling the temperatures. You'll likely need to replace but there's some quick ideas and I've used WD-40 for the lubricant for a temp fix until a replacement arrives. – Pimp Juice IT Jan 4 '16 at 6:17
  • Maybe you have a buildup of dust inside the computer that's causing it overheat. – BillDOe Jan 4 '16 at 6:19
  • I see your edit now that it's a graphics card fan. Those can get very hot so be sure the fan stays running but you should be able to take out the card and turn the fan with your finger and see if it's worn out, some obstruction, etc. Hopefully the card has a fan part that you can detach and replace separately. I would not run it without the fan for sure and especially if it's a high power one that gets hot or else it can get damaged so hopefully when it gets quiet, it is NOT stopping entirely so you probably need to crack open the case and look at it while it does it to see what's going on. – Pimp Juice IT Jan 4 '16 at 6:25

Browse other questions tagged or ask your own question.