X301 Fan Noise

[Nifill]

My X301 is now just over 3 years old.
Approx 6 months ago i started having noises from the system fan. ( I have SSD so there's no rotating hard drive).

I called IBM support, since the device was still under warranty, they arranged repair with the main UK repair provider.

They provided a quick turn around and I had the unit back within one week.. it looked brand new and I was impressed.

Ran fine for approx 6 months and now I have a recurrence of the same fan noise.

Bad batch of fans?
Did the repair operation actually change the fan, or just oil it ?
Keen to hear of any similar experiences or suggestions.

Nigel