7900X 100C at Load

[Moondoom]

Hi guys, it seems that I have some really strange issue with my CPU temp.

Long story in short:
Mobo: Asus R6E, bios: 1002
CPU: 7900X - non delided - Water block (EK CPU+VRM combo unit)
GPU: Strix 1080 TI - Water block (EK Block)
Cooling loop: Full custom loop, 360PE(45mm) + 360SE(30mm) + EK 140 Res + D5 Pump combo (glass) + 6 EK Vadar fans 2200Rpm
Case: Be Quiet! Darkbase Pro 900

My temps are all fine, except the CPU. But the CPU is horrible: Under load at Stock(!) the temp goes up to 70°C-75°C.

If I overclock it a bit to 4.5 Ghz, at 1.15V (Stable, no issues and still under the recommended 1.2V) CPU package temp goes up to 100-102°C under Cinebench.

Additional info:
Room temp around 23°C, Water temp at idle 31°C - 38°C under heavy load, GPU at 32°C idle - 45°C in gaming, VRM at 36°C idle - 65°C under heavy load. Pump is always on 100%. Fan speeds are irrelevant since the water temp never exceeds 38°C. CPU 35-38°C idle - load temps...100°C or higher...

I know that the Skylake-X CPUs are hot, but I have never seen temps like these for the CPU under this low voltage.

I have tried the following things:
Reseat the CPU block.
Re-apply thermal paste.

Do you have any suggestions what can cause these temps?

 

[Moondoom]

Does the CPU waterblock have an in and out? Are they the right way round?

Yes, the WB has an in and outlet, all connected correctly.

Is the block making good contact with the heatspreader?

Yes, all good, the thermal paste spread equally.

And, I have to ask, if it was new, are you 100% sure there was no protective film on the bottom of the block that you forgot to remove?

There was, but I have removed it before the first use.

 

[Moondoom]

Ok, found out some things myself. For some reason if I use adaptive voltage, the 1.16 base, -0.001 I still get 1.22-1.24 (according to HWInfo). Temps go up to 103°C, 2 cores are throttling. However if I set the voltage to 1.16 Manual, it runs "only" at 93°C. The system is stable at 4.6 - 1.16 Volts. After I set the voltages manually, most of my issues seems to be gone.

 

[Moondoom]

I do want to delid the CPU, but I have never done it on any of my other CPUs, so I'm afraid that I would damage the unit itself. Also, it seems like ocuk is out of the delider this time.