Question multiple parts changed cpu quickly goes to 99C in BIOS

[a39232]

So I have recently gotten a computer back from a customer and it has a G3258 with a H60 that was 10 years old was super corroded etc. cleaned it and it still slowly goes to 100C then I upgraded to a 4790 and it does the same thing. Changed the cooler to a new H60 elite and the same thing but it reaches 99C even faster. So my guess is the motherboard sensor is bad but idk if the sensor is on the cpu or the motherboard ? The interesting the is the G3258 runs fine it does throttle but you don't notice it much but the 4790 goes to 800mhz and then eventually black screen and reboots. also with the new cooler the air is lower than room temperature to me and around the socket it feels room temperature or less.

Mobo: MSI Z87I gaming AC
PSU: corsair cx750M
case: Caorsair 250D
ram 16gb teamgroup 1600mhz
OCZ ssd 120gb Aand 1TB hhd
cpu cooler :H60 Elite
gpu sapphire HD7770

 

[boju]

I doubt it's a bad sensor if symptoms are actually bad. Is the pump running with the new aio? Both tubes feel about the same temperature wise?

Try an air cooler. aio isn't necessary for these processors anyway.