So I took off the cooler and and cleaned off the thermal paste and applied a new layer.
When installed Windows and Speedfan I got a temperature of 31ºC at idle. When I transcoded a two hour video I got temps of ~60ºC on Core 0.
How is that with a stock cooler and a Corsair Graphite 600t White Edition with all the stock fans. I've just no frame of reference for this.
Those are very good temperatures for the stock fan, as long as the temperatures remain like that you have nothing to worry about.
My 2500k idles at 30ºC to 35ºC depending on the room temperatures (that is with an Noctua cooler and a 4.5GHz overclock) and never goes higher then 55ºC under load (unless im stress testing with prime then it hits 65ºC) but long story short .....60ºC is nothing to worry about and is perfectly safe.
You may think it is irrelevant for me to list my temperatures as im not using the stock fan and I have overclocked the CPU, but its just to show you that 60ºC is perfectly safe
I hope this has helped to put your mind at ease a little.