CPU temperature question

Good Monring!

This is my first time posting on this forum, but definately not my first time viewing. Everyone here has been instrumental in my most recent computer build; so thanks for all who post and answer!

Now that's out of the way, on to my question. Just built my second system, and I feel pretty proud of it. However, this is my first time using liquid CPU cooling, and my first time overclocking. That being said, I've never really paid attention to any temperatures except my video card in my old, poorly ventialted heat box. My new system runs very cool, and now that I'm monitoring the CPU temps I have a question.

I'm a bit paranoid about the thermal contact, so i'm wondering if it is normal in an intel burn test for the following to happen:

1. Idle temp: 27-30C
2. Start burn test at maximum and temp goes to 57-60 in literally one second. hangs out stable at 60 for as long as the test is running
3. When test is stopped or complete, temp falls back to 30C in 1-2 seconds...

My thoughts are that temps are falling so quickly because the cooler is working well... just not sure why they're rising so quickly. Is that normal? I'm using 2 different monitoring programs (F-tune and HWMonitor) and they both read the same.

Sorry for the long-winded nature. Just new to the OC game and don't want to mess anything up.

Thanks!