75°C in the middle of winter.

[AmericanSteam]

I had been having a computer overheating issue for the past week and it was getting worse. CPU was running hot when playing TS. It was getting to 75°C on all cores after about 5 minutes. Temperature during times not playing TS they were close to normal but a bit higher. The cooling pump and reservoir were about 1 year old and the pump was making a bit of noise, it sounded like it was cavitating. I ordered a pump and reservoir, swapped it out and started the computer and bled the system. All was well for 30 minutes then the overheating returned. I tore everything out of the case and vacuumed, wiped and removed the dust bunny warren, found a screw I dropped, dressed all the wires to make it neat and tidy. I put it back together and still had the same problem. Being a retired auto technician I thought about it in automotive terms. The water pump is good, no leaks and it does not have a thermostat. I took out the radiator and took it to the sink and did a flow test and a piece of impeller from the old pump came out. This was apparently blocking the flow through the radiator. Just another thing to look for when tracking down a overheating issue.