A heat issue? When I Play a game on mine, after a while everything gets hotter and one of my fans kicks into high and makes a lot of noise. It dosen't happen if I take off the side cover. Maybe the thermal interface material on your heatsink wasn't spread out properly? Just a thought, Good luck.
I recently had to reinstall a new hard drive. Since then, my computer has been very noisy. I narrowed it down to the fan, but WHY would that happen, and what can I do about it? It's so annoying, I cannot leave my computer on for any period of time.