MSI Z390 Gaming Edge AC
My temperature on CPU is 60°c during idle and can go up to 99°c while playing games. Is it possible that my i9 is damaged or something? Cause the heat increase very rapidly.
The only way to check is to pull the liquid cooling unit's block (thermal mass) off the processor and look at it. In so doing, however, you are going to have to replace the TIM anyway. If you have replacement TIM on hand, great, you can move forward. If not, get something like Arctic Silver 5. When you are ready, remove the block from the processor, wipe clean both its bottom surface and the processor's top surface, squirt roughly a pea-size glob of TIM in the direct center of the processor's thermal plate (top surface) and then place the block back on the processor. Make sure it is tightened down well and evenly on all four corners.
With Windows 10, there are a lot of background tasks that the processor is always running (especially when you are not doing anything in the foreground), so 'idle' is a relative thing. In general, though, you should be seeing temperatures in the 40's. Seeing the temperature change rapidly and getting up to 90 is not abnormal, even with a liquid cooling unit. If the temperature is going into the 80's or 90's, you should be hearing both the fan and the pump in the liquid cooling unit speeding up. If you are not, there may be something screwed up in the BIOS's fan speed control configuration or in your installation. The fan and the pump must both be connected to 4-pin fan headers on the motherboard that are responding to processor temperature changes.
Hope this helps,