Hmm…I think I've had this happen before. Coming from my experience, it's possible, unfortunately, that the Blu-ray laser used to read the games is coming close to being dead.

I remember hearing those noises when I had my previous PS3, and was able to eject the disc manually instead of the system automatically ejecting it. Also, I did have the PS3 for that same amount of time, if I recall.

I'm really hoping that's not the case, but it sounds like you're getting the Blu-ray Laser of Death. If it is, I'm really sorry.