I bought a new rig a month ago and only recently realized higher-than-average CPU temps. Took a look inside and whaddya know, heatsink wasn't locked in properly. After re-centring the heatsink (temps are a cool 35c now) I've been hearing a loud rattling noise coming from the heatsink. I've stopped all the fans inside the case with my hand, so I know it's not any of them, but it seems to be the heatsink itself. If I push on the side or on the middle of the heatsink, the rattling goes away, but as soon as I let go, the noise comes back. It's just the stock heatsink that comes with the i5. Does anyone know what could be wrong?