Hopping CPU temps

[stuckonthis]

Since my machine was built last year I have had cpu temperature readings on idle like '16 17' 19' 21' 18' 33' 18' 29' 26' 32' 20' 27' 19' 23' ect: nothing running in the background.  I'm wondering if it could be a thermal paste issue but I really don't want to be messing with the cooler as I will risk getting paste on the mobo or breaking cpu pins, i've seen the mess it makes it's like waking the sleeping giant taking that b*stard off as I will have a very delicate cleansing job to do, is that likely the reason for this temperature behaviour?

[podkall]

10 minutes ago, stuckonthis said:

Since my machine was built last year I have had cpu temperature readings on idle like '16 17' 19' 21' 18' 33' 18' 29' 26' 32' 20' 27' 19' 23' ect: nothing running in the background.  I'm wondering if it could be a thermal paste issue but I really don't want to be messing with the cooler as I will risk getting paste on the mobo or breaking cpu pins, i've seen the mess it makes it's like waking the sleeping giant taking that b*stard off as I will have a very delicate cleansing job to do, is that likely the reason for this temperature behaviour?

is the CPU usage constant 1-0% or is it 1%, 5%, 7%, 1%, 3%, 2%, 8%, 2%, 1%? because if yes then you get the idea what could cause it.

[stuckonthis]

Here are some readings under Core Temp: