Alright
So you probably don't have the best airflow in your case that's why idle temps are so high, which again isn't a big deal (I bet at idle the case fans are dead silent)
Since the cpu cooler manages to keep the cpu cool under load there's nothing to worry about. The noise will be due to a high speed fan
If it has been quieter before it's most likely due to dust. Freeing the fan of dust will help
If it was like that since ever and suddenly starts to bug you for some reason, you'd need to invest in a new cooler (make sure your case can support it before buying)