for a start, there is no point in using an aftermarket cooler on an i3, since you cant overclock it and it doesnt produce much heat. You should also be aware most motherboards have fan speed control, if the hyper212 is running on its lowest fan speed or set to auto, the fan may not increase in speed till it hits at least 50C, therefore temps may be no different. you have nothing to worry about anyway, its far from overheating.
so, is everything normal?? including the difference in temperature from both cores??
i do know that the i3 doesn't need the hyper but i got it when i was using the Celeron G530, not for the temperature, but for the sound, the stock cooler from the celeron was annoying, and now that i have the i3 i decide to use it
but the reasons that makes me wonder if the temps are normal is because the hyper drop the temperature from the celeron from 32 to 19 so i was expecting something similar with the i3, that and the reviews from amazon and newegg where some people say that the temps are 25-30c on idle
The temp on the low core is impossible, actually. There's no way it would be lower than ambient with an air cooler (your case temp appears to be 29-30C, and I imagine room temp isn't much lower than that (maybe 24-26C)). The general rule is that your idle temp will be 5-10C warmer than ambient using air cooling, with the lower temps achieved using a top end cooler.
Temperature discrepancies between cores are normal (especially true with Ivy Bridge.) I have ~10c temp difference in my 3770k. On HW Monitor your your core #1 temps dropped 4-7c and your core #0 dropped 1-4c. Not great but the stock cooler is really enough for an I3, a 212+ is overkill. You could check out your Hyper 212 fan as well to make sure it is working and that it is upping it's RPMs when the chip temp increases.
However, as DJDecibel pointed out, your temps for Core#1 are lower than ambient and you may have a faulty sensor on the CPU or the mother board is not reading the sensor correctly.
so you think the problem is the sensor? can i fix it?
Semiconductor thermal sensors are highly non-linear, particularly at low temperatures.
Calibrating thermal sensors on a CPU would require warming/cooling the CPU to specific temperatures on a test rig and reading sensor data to map the response curve. This is a time-consuming process that is much beyond most people's abilities and if Intel bothers doing it at all, they probably only do so at critical temperatures such as where they want thermal throttling and shutdown to occur, both of these being over 90C.
At such higher temperatures, thermal diodes become much more predictable so it is quite possible that Intel simply relies on physics rather than bother with any formal chip-by-chip or calibration.
In other words, can't fix it. The CPU's thermal sensors were never intended to be accurate, at least not until temperatures reach levels actually worth worrying about.
just an update, today i built a new pc for my brother, using my old celeron g530 and i decide to test the i3 on the new motherboard to see if the heat sensor in mine was the cause of the difference on the temperatures....and no, the temps are the same on the new pc, 14-16c on core1, 35-38c on core0, then i put back the celeron on my pc and it was at 18c on core0, 19c on core1....
so, i guess the sensor that doesn't work as it should is the one on the i3 CPU....bad luck i guess