My white macbook (around 3.5 years old, version 10.5.8, 2.2 GHz, 4 GB) has been rather noisy for quite some time. I never really noticed it until I went to college, took a CS class, and brought my computer to class (which was so loud enough to get awkward glances, but not loud enough to be disruptive). I've been recently looking into fan noises and such, but all of the problems have been simply due to overheating caused by high CPU usage. I do overheat my computer often, due to programs such as handbrake, but when I use a program like that I expect my fans to be running high. However, when I start up my computer after an evening of having it off, it goes straight into noise-mode. Attached is a picture I took, showing my activity monitor and my little smcFanControl panel in the upper corner. As you can see, barely any percentage is being used, yet within the first 10 minutes my computer heats up to 66 C and the fans run high. And my min speed for my fan is 1800 RPM, so I'm not forcing it to overwork. Edit: I cleaned my fan (which was pretty dirty) but the fan still runs at a minimum of 4000 RPM, even with 95% of my computer idle and the temperature at around 55 C. I restarted the SMC, and that didn't work either.