Here is a friendly reminder to clean your pc out if you haven't in a while, like 6 months...particularly if your case is not filtered..
Today I did just this and was surprised at the dust accumulation on the various fans and fins.
Take your graphics card out too to really make a decent job of it.
I actually took the top cover off mine to clean the heat sink fins this time and it was just as well because the fan may have been going around to see and hear and appeared clean but the air wasn't going anywhere inside...
Take some time to tidy up the cables too if they are inhibiting airflow in the case.
All back together and running the temps have dropped noticeably and it is also much quieter.
Have a nice day :o)