I had the same problem with my l502x, i resolved the issue with a fresh new windows 10. I use to have windows 7 for a long time and since i have upgraded to windows 10 everithing is normal. Now and then the fan does make some noise, but not for long. It will do ok with a deep clean, i mean take all the dust out and use a bit of profesional oil to put at the base of the fan to make it work smoother. Thats what i did and no problems now. Hope it will work for you to