H100i unstable temps

[HereticIcue]

I have a Intel 11700kf and I was using a h60 to cool it but it was too loud so I got a h100i I turned the PC on and the idle temp was 35  then spiked to 40 then 50 then back down to 35 and it keeps doing this ....the water temp is 28 degrees but the temp keeps spiking. I played a few rounds of mw2 and the temp stayed around 55 to 60 so that's good but I turned the game off and the temp kept spiking do I have a bad pump?

 

 

[c-attack]

No. A pump that can’t hold its rpm will be very obvious. These tend to make a lot of noise and have clear large 300 rpm+ shifts in speed at random intervals. The coolant temp sensor is in the block and sluggish water movement there would also show as coolant temp spikes to match the cpu spikes. 
 

I am not sure I would consider 55C to be a spike, but it seems like rolling temperature changes reflective of cpu activity. If this is new behavior, you will need to look at cpu activity in the Task manager and check on any new programs, including CUE.