That is high, but depends on your ambient room temps...can you list that? Also- 30-40 C is quite a swing...which is it? Assuming the high/low of the idle and load temps you have above, maybe ambient temps are impacting more than you think.
What are you using to load the CPU? Did you do any tests with the CPU at stock speeds?
You may want to try reapplying your thermal paste and make sure the same pressure is on all the screws.When you tighten it down go from one corner to the complete opposite than move the the other set and tighten them a bit more and keep doing that till its all tight.whats fan speed setting are you using?
Not necessarily. If you haven't had the paste on for long and are careful, you don't need to reapply it. You may need to do that anyway as it may not be set up ideally if you are seeing such high temps. I have a 3770k at 4.5ghz on a Zalman 320 kit and it has never gone above 80C. Make sure you have plenty of airflow in your case too.
How do I know if I need watercooling or air cooler upgrade?
-aka- My temps seem to be hot on my CPU and/or GPU!!
-aka- Do I need watercooling?!
Not so fast. I’m not trying to discourage anyone from going out and contributing to the economy by spending their money on a new cooler or full-fledged watercooling loop. However, here is a simple way to test whether or not your cooler needs updating or if you simply have poor case airflow, in which a cooler upgrade would still have little effect (watercooling loop would still provide improvement, but still dependent upon ambient temps and radiator placement/airflow).
Remove the side panel of your case. Take a house or desk fan- turn on HIGH and blow air into your case. Run your benchmarks, game, Fold, encode video, etc…see what your temps are. Compare with the temps you get with your case side on, and no fan. If the temps drop 5°C or more, you have a case airflow issue inside your case that should be addressed before ever replacing an air cooler with another air cooler. Watercooling might help, but depending on your desired temp ranges and budget, updating/adding fans might be the only thing you need to improve to get temps where you want them. If your temps remain the same or within 1-3°C, you might have a minor airflow issue (or ambient temps are different than when you ran your baseline test without the fan). If you still are unhappy with your temps, this is when considering a cooling upgrade is a good decision.
ALWAYS when ever you take you heat sink off you need to reapply new thermal paste. I can say for sure that those temps are quite high and even though my 2500k isnt an ivy bridge i idle around 30c and max out stress tested 69-73c at 4.5ghz on quiet mode. What are your temps in game for about 20 minutes?
It honestly sound like either the pump isn't running,very bad thermal paste job,or a very very bad chip.My guess is on the pump not pushing any coolant.I also suggest what rubix suggested.See if the pumps even running .You will hear it with no fans on,even with the fans at quiet settings you will be able to hear it if you put your ear by the case. If it is running rotate the rad and pump itself in all directions multiple times.
Just wanted to say thank you to all you guys, I re-mounted the pump with some new thermal compound and realised that the backplate wasn't properly orientated on the motherboard. Temps are now 40C lower under load