I own a MacBook purchased in January of 2007, still under Apple Care. Long story short is that the past couple weeks I noticed a heavy clicking/whirring sound coming from the front left of the machine; the sounds were seemingly indicative of imminent drive failure. I backed up my important data and went to the Apple Store nearby today, at which point the drive was replaced and I had the system reinstalled. After returning home, however, I noted that the problem still exists. Is there a fan right near the hard drive that is making this noise, and is it dying? It is an intermittent constant clicking, with an occasional "vroom"/whirring sound. Heavy system use (i.e., playing a game/watching a video) seems to make it stop or ease up, presumably because the fan (if that is the issue) is forced to spin at a higher speed. I have a video recording of the sound which I could upload by request, but I am wondering if anyone has experienced this issue. Something is wrong because this has never happened until a short while ago, as previously mentioned. I would just like to have an idea as to what the issue likely is before I have to go back to the Apple Store a second time.