Originally Posted by patonb
Its probably due to age.
Have you noticed any increase in temperature? If yes, reinstalling the past and fan may fix it.
If not, then its wear.
If he has had that original stock heatsink fan on with paste for the past 6 months he is due for a normal rechanging of paste.
Since he also said it has become more louder he may have some dust in his heatsink fins.
Artic-cooling on the original heatsink fan should do it justice and it will hold steady under 3.8ghz on normal warm days.