Well the title is clear right? I ran the Apple Hardware Test (AHT) because our model was from 2012.
- Switched off the macbook
- power on macbook
- press and hold ‘D’
I ran the extended and more advance test which takes a bit longer. But it gave me the message:
4mot/4/40000002: exhaust-0
it said that the fan was broken. It was exactly what I expected due to the noise of the fan.
Our model was an A1466 and the fan replacement would cost me 145 euro at an Apple care center, so I bought the part online for 26 euro.
Here is the step by step ifixit guide. Please note that you need a P5 pentalobe screwdriver which is Apple specific. I bought it online for 5 euro.
I have spend 38 euro inc shippingcosts. You can get the screwdriver really cheap from aliexpress, but the shipping takes a long time and I cannot live that long without my macbook. Same for the fan it seems. You can get both for 9 dollar without shipping costs but it will take a while to arrive.
On the left is the new one, right side is the old one.
The hardest part was opening the zif connector to reattach the data kabel for the new fan.
The zif connector is so small that it is hard to open.
Running the hardware diagnostics tool can confirm that replacing the fan is a succes. You will not get the 4mot/4/40000002 exhaust error again.
Good luck with the fan replacement!