Hot running CPU

[Schattenbrot]

I'm running a i7-6700K @4.2GHz with a Shadow Rock 2 cooler on top of it and am wondering if my temperatures are a lot too high.
In Idle I got temperatures between 60 and 70C
while gaming it mostly is constant at ~90C with some spikes to the 100C.

My PCsystem is cooled by 1 CPU-fan and 4 more (2 in front into the system, 1 in the back out and 1 in the back/top out as well)

 

[Rakanyshu]

High temps, have you dusted your pc case? It could be the cause, be sure all your fans are spining and how did you applied thermalpaste?

 

[Schattenbrot]

I applied the thermalpaste myself the first time today so was a a bit unsure.

I removed the cooler, cleaned the cooler and CPU with high percent Alc, put a peppercorn of paste in the middle of it and put the cooler back on again. I even removed the cooler instantly to see if it is enough and not too much, cleaned it again and used the same amount of paste again. After that I put the cooler back on it.