I've got a question here... I already think that I know the answer.
3 or 4 months ago I bought this new PC and also ordered an Antec Kuhler h2o 620 for my Intel i5 2500.
Now I was playing Far Cry 3 Co-op while skyping with a friend and when I closed the game I suddenly realized that something was smelling like burned toast. After a second or 20 I found out where it was coming from: the back fan (where the antec Kuhler is connected to)
So as fast as I could I installed Core Temp and saw that my cpu temp was still around 80 degrees. Then I closed Far Cry and the temps dropped to around 30-35 degrees for idle.
So I downloaded Prime95 and started doing tests. I actually reached 85 degrees max.
i5 2500 isn't overclocked and the Antec never gave any trouble.
Ok, sorry guys. Already fixed the problem. There was a problem with the custom fan on the computer case. One of the cables wasn't attached to the PSU properly so it wasn't working well. Now it's fixed.