CPU temp high at low usage

[Question McQuestion-Answer]

So I made my first build last year and have recently added more fans hoping to improve airflow and make it quieter. I have an 9th gen i9 with liquid cooling (golden field sf240 (best ‘value’ water cooling I could find on Amazon)). I downloaded hardware monitor to track the temperatures while a game was running so I could see what kind of headroom I had. GPU (rx580) runs at 100% with high settings in Warzone but temps are very good between 70 and 80. Very surprised to see the same can’t be said for the i9 which is running at around 40% and hopping between 90 and 100 degrees Celsius. From what I can see that’s not good. I have the radiator front mounted with input fans in front and water pipes on bottom, and vent fans over and behind the motherboard/cpu pump. Could I be doing something wrong or should I assume that the cooler is just no good?

[WoodenMarker]

What motherboard are you using? Are you using default bios settings?

What rpm is the pump and cooler fans running at?

[LogicalDrm]

Which i9 exactly? What mobo? Can you post some monitoring details? Have you checked that your pump is working and cooler mounting is all good?