De-lid or replace?

[Nekroskope]

Specs
i7 6700k@4Ghz
Asus z170 pro gaming
32 Gig Kingston Hyper-X @2400mhz
GameMax GM1050 1050W Semi-Modular 80+ Silver
Asus Nvidia rtx 2060
2X 500gig hdd
1X2Tb hdd
1X120gig ssd
Corsair H100i watercooler
3 case fans 1x120 @ rear, 2X80 at front of case, one sucking one blowing.
Case mid range Aerocool
Within the last 3 weeks the computer has been fully stripped to individual components, brushed clean with a blusher brush and cleared of all dust.
The aio has been removed, cleaned and thermal paste reapplied twice.
Mobo, CPU and ram are 5 years old.
When I fire the system up the cores run straight up to 95-98 degrees and stay there. At idle and at full loads. 2 Ark servers, the game, OBS, Audacity etc. etc.
The core temps have been checked on both speccy and iCue. And if I reboot the comp the bios kicks in with overtemp warning and I usually find the cores running at 82-89 degrees.
To my mind it would seem,after 5 years, the thermal paste under the ihs has become degraded and isn't working to its full potential.
Due to Covid and certain health problems I have, replacement mobo bundle isn't currently an option. Ideally I would like to get about 2 more years from this rig then I should be able to afford to upgrade to a mobo bundle with ddr5
I have boiled it down to 2 solutions.
1 Pay for a professional de-lid service.
2 Flash the bios and replace the CPU with a second hand i7 7700k
The de-lid option is by far the cheapest, but will lead to several weeks of comp downtime. Flashing the bios and replacing the CPU is a lot more expensive but it will be done and dusted within a few hours although there is the problem of buying 2nd hand. The processor could last a week, a year or a decade.
What would your thoughts be on this problem?
Many thanks in advance.
Nekroskope

[Mister Woof]

Are you sure the cooler is functioning and installed properly?

[Nekroskope]

According to iCue, yes. The cooler was purchased at the same time as the bundle, so it's been this way for 5 years, but the temps are recent.
Solution temp is around the 57 degree mark.
 

[Mister Woof]

Well I can speak from personal experience that delidding the CPU and applying liquid metal is easy and effective, but I would make sure the cooler isn't the problem first.

 

Maybe put the stock cooler on to see if its still bad?

[Nekroskope]

I'm starting to think it is the cooler.
Just taken the side off and there is no heat in the radiator or the pipes, Pulled up iCue and it's saying it's rpm is 4250 up to 4750, It's max is supposedly just below 3000rpm.
Bugga. lol. Still, cheaper than a 2nd hand 7700k lol.
I'll contact the vendor tomorrow and pick their brains, but I think I'll be ordering a new cooler tomorrow.

 

[crazyfrog]

The cpu is booting it’s not the cpu it’s clearly the pump. 6700k came with a stock cooler put that on lol. Also did you buy the 6700k used it may have been resealed with liquid metal and moved under the heatsink. 

 

if you intend on having good cooling like a Corsair h100 it’s absolutely pointless not delidding, you can have scenarios where the cpu is running 90c and the radiator is about room temperature.