Those CPU temps are fine, especially if you're on stock cooling.
I'd bet money that it could be your PSU. The ones that are included with cases are often cheap no-name brands. They often use cheap fans that rattle or whine, and the cheap electronics inside also contribute to a pretty short life-span or inconsistent voltage.
Try downloading SpeedFan and seeing what your GPU is running at just in case. Also, please list your specs, we can help a lot more if we have an idea what you're working with.