I have just finished building a new pc from the ground up. I'm using the intel 11900k on the EVGA Z590 Dark along with an EVGA 3080ti ftw3. (RAM - 2 x 16Gb G.Skill Royal Elite 3600mhz CL14) I've installed EK water blocks on both the CPU and GPU. All powered by EVGA 1300 P+.
During standard use everything is fine. - All stock settings. 

However, during a benchmark with TimeSpy, I had heard a buzzing sound. Which originally sounded like two bits of metal rubbing (or ice pressing on Aluminium) It was only for a small moment and then the TimeSpy test "crashed" stopped working. 
I thought it was a temperature issue with the CPU as it had peaked at 78 Deg (intel boost to 5.1Ghz) so I have adjusted the fan curves and ran the test again.... all is well. 

Day 2 I play call of duty nice and smooth so I switched to warzone to play with a friend, System crashed after 10 minutes due to CPU temps being 70 deg. 
I have now disabled intel boost. The CPU is back at 4.8Mhz max and the temps are nice and low in the 50's. Now with the fans not running as loud I can hear the buzzing again. ONLY during the game play. GPU is at 48 Deg max and cpu at 60 deg max. But the noise got louder so I shut the game down and ran Time spy again. 
The noise presented itself during the initial video and during the GPU tests. During the CPU tests it was completely silent. 

I Have run HWinFO64 and will attach photos of the temps etc. 

On a side note I can drain the loop in the morning, unfortunately this is a hard loop so it wont be easy to disconnect reconnect. But I am open to all and any suggestions on the matter. 

This is the video. at 12 seconds TimeSpy begins Graphics test one. Prior to that just wind / Fan noise.

This NOISE is the main concern.

https://www.youtube.com/watch?v=-KVQsoHIhWc
 
 
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https://ibb.co/ynjcXDZ
 
 The "crashes" that were experienced were not total system shutdowns. The program being used at the time closed off completely and I was left on the home page.

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From the description, the load, and the video, it definitely seems like the GPU making the noise to me.
 
Also, your CPU being at 70-78°C shouldn't be causing crashes. Mine crashed at around 100° once during BF5. I've seen instability with a couple clock-settings (running 5.4GHz or my memory timings too tight, but yours are stock), but the crash wasn't temperature related. Your clocks nor temps seem high enough to cause the crash alone (in my opinion). I am quite jealous of your GPU temps though.
 
Does the system event viewer show you any information from when it crashed? (right click This PC -> Manage -> Event viewer -> Windows Logs -> System, then find any critical errors or warnings right before it crashed).

The Event Viewer doesn't say too much. It states Kernel-Event tracing in the warning section, then Error Kernel and Critical Kernel.   One of the codes that came up.     error: 0xC0000188 
The others were blank in the Critical section.
another warning at the time of the crash came up as this "Device send an incorrect response following a keyboard reset."

Kyrog
The Event Viewer doesn't say too much. It states Kernel-Event tracing in the warning section, then Error Kernel and Critical Kernel.   One of the codes that came up.     error: 0xC0000188 
The others were blank in the Critical section.
another warning at the time of the crash came up as this "Device send an incorrect response following a keyboard reset."

OK. Not always much there, but worth checking. So when you say "crash", did you get a BSOD, or did the whole system just reboot like a hard power failure then turned back on? There have been several instances of power supplies not being able to keep up with the current spikes of the 3080ti's, 3090's, and even 3080's, but you have a brand new 1300W PSU. I'm not sure if anybody has a better suggestion for HWiNFO64 that would have readings from your motherboard as it doesn't seem to be getting any, but I'm curious if you can log your +12V rail voltage to see if it is dropping at all during heavy use. 
 
Edit: could still be worth checking the log there, but after talking to you elsewhere, you've indicated that you didn't get a big power-cycle crash, just a crash to desktop. There may be some other driver or setup tweaks others may have that could help. I may be a bit out of my element here (insert Donny reference).

I have an ASUS Z590 board and a 3090.  Time Spy crashed on that system also.  I talked to the Developer over on the Steam site and all he said was it wasn't their software.
 
I haven't used the Benchmark since that time but I did not have problems with some of the other Benchmarks.
 
If the noise is that buzzing type sound, that sounds like a fan or pump is hitting something.
 
It looks like you are experienced with building machines, just keep in mind the hot air from the video card may be getting back into the intake fans.

I am mainly just using the software for a load test to get the noise to show itself. During the CPU test it isn’t present at all. and the temps are below 50 deg I just cannot fathom what the noise is. i don’t want to ignore it (it’s a bit loud to ignore) just incase something pops and i’ve got no gpu anymore

Responding to your PM. Sounds like coil whine to me. It's possible one of your components may have been dampened with your air cooler but due to the change of your assembly from going to a air cooler to a waterblock, the component may not be dampened anymore and now you can hear it.

I don't know the best means and methods to fix this. But there are many threads out there of people dealing with coil whine.

If the crashes occur the momen the coil whine happens then you should probably RMA the card.

Edit: so it sounds like you figured out your crashing issue due to a OC? Well if that's the case, you just have coil whine. You'll have to figure out which component it is and dampen it somehow or RMA the card if it's that loud and bad.