Game causing CPU to overheat and crash computer upon launch.

Sounds like the liquid cooler either isn't working correctly or it's not installed correctly.

I would start by turning the radiator fan speed to 100% in bios.

So I tried that— set all fans including gpu fans to 100% which I think is what allowed me to get past the initial loading screen, but still happened after loading up a game. 

just seems odd that it’s only battlefield and not any other game, no? 

I should also add I’ve had this pc for >18 months without this issue 

If the CPU temps are rising above 90 °C then it's a CPU cooling issue. 90 °C is the maximum operating temperature for that CPU.

Here's some CPU stress test software to see if the CPU is overheating.

https://techguided.com/best-tools-to-stress-test-p-cpu-ram-gpu/#2

HWiNFO is the best temperature monitoring software.

https://www.hwinfo.com/

You could unscrew the existing cold plate and pump off the CPU, clean off the thermal paste with rubbing alcohol, put new paste on, and reattach the cold plate and pump back on top of the CPU.

Maybe that will fix the CPU from overheating. Perhaps Thermaltake didn't screw the cold plate down tight enough on top of the CPU. Also check that dust isn't blocking airflow through the water radiator fins.

You might need to install a new CPU cooler. Gamer's Nexus does the best CPU cooler testing and reviews. I would get an air cooler for around $40 but make sure it will fit in the case. Air coolers are big.

Mount the air cooler as far away from the graphics card as possible. Sometimes one side of the air cooler has more clearance than the other side, so double check by rotating the air cooler 180° before screwing it onto the motherboard. Both air cooler fans should blow air in the same direction. Blow the hot air up and out of the case.

Thermalright Peerless Assassin 120 air cooler review.

https://youtu.be/Mm4hyIHe1PM

https://www.amazon.com/Thermalright-Peerless-Assassin-120-Cooler/dp/B09LGY38L4/

Or you could buy another 120mm all-in-one (AIO) water cooler for $90. Be careful because most 120mm AIO coolers have poor cooling performance. This is the best 120mm AIO I currently know of. It performs similarly to the air cooler I listed up above.

https://www.amazon.com/DeepCool-Dual-Chamber-Anti-Leak-Infinity-AM5-LGA-1700/dp/B09Y1LTTZJ/

I had to downclock the CPU for Battlefield on a friends 5600X to allow him to play the game with reasonable temps.This game is very very CPU intensive. His CPU runs happy at 4750MHz (all cores) at 1.25Vcore, plenty of power and lower operating temperatures as the motherboard would pump over 1.4 Vcore voltage to allow the boost clocks...and super high temps. Cause was a bad motherboard speed/voltage Bios implementation that would trigger like an Over Current Protection while firing up battlefield.

Due to silicon quality your mileage may vary

Start off with setting 45X CPU multiplier and set 1.25 VCore in the bios and test, if stable work your way up

Make sure ya got a good airflow !
I did downclock also (5300mhz , 1,28Volt) , but i managed my pc Fan's , reinstalled all of them them.
I got liqued cooling (AIO) , now my 3 fan's for AIO are intakle (fresh / cool air) and not exhaust already warmed air , that get even hotter when it go true AIO radiator. (cpu will not cool down enough)

I did move AIO + 3 fans on iradiator to side panel, and did set 3 fans in top from case to exhaust air !

1 fan at the back of PC for exhaust and 3 fans at the bottem of pc for inhaust 🙂
I run now at 5500 mhz with i9 13900k without issues, temps get at around 75 / 80+ , all utlra , 165Mhz monitor , 6000 Mts memory 32gb (xmp 1)

PS i did install Thermal Grizzly contact plate about 2 weeks also, that did help to lower temps (about 6 till 10C lower) but still got issues at that time , so thats why i reconfigured AIO and all fans in my pc case 😉

Cheers