That really sounds like heat to me. If you havent already done so, i suggest investing in a couple cans of compressed air. Remove your side panel from your case and blow all the dust out. If your comfortable removing the video card, remove it and hold the fan still while blowing the dust out of the heat sink. Repeat with cpu, psu and case fans. I always recommend holding the fan still because you can over spin them and damage the bearings. Let us know the results and we'll accommodate you more from there.