All, I'm looking for some advice. Recently I've noticed that the right hand side fan on my rMBP 15 (bought in March 2013) has a constant low whining noise. This can be heard as soon as I switch the MacBook on, until I switch it off again after use. It can only be heard when in a quiet environment however it's becoming pretty annoying. When putting my ear up close to each fan, there is a noticable different in sound between the left fan (which is working properly) and the right fan. I have tried both SMC and PRAM resets however the problem still persists. I've recorded each fan, both of which can be found at the links below. Do I have a case to book an appointment with a 'Genius' and get a replacement fan installed? Normal Left Fan: https://soundcloud.com/jaisullivan/rmbp-left-fan 'Faulty' Right Fan: https://soundcloud.com/jaisullivan/rmbp-right-fan All opinions/advice will be greatly appreciated.