MacBook Pro-peller

My MacBook Poop is making really awkward noises, it's the fan. This began maybe in late November. Intermittently.

So, being a diligent person who understands the difficulty I will experience if the machine overheats, I booked it into the Apple Store in Covent Garden before Christmas - where it was thoroughly checked out and proven that the fan was not making any noise, running perfectly, 'as new' in fact, and I was even complimented on just how pristine the inside of the machine is when coming up for two years old.

'Perhaps there was something in the fan that dislodged but there's certainly nothing to be concerned about now. Keep an ear out for it coming back'.

Well. The next time I used the machine, it came back.

Funny that eh?

It sounds like mini Scalextrics heard through a muffler.