New Fan Clutch - Is it Defective?

[Btaztic]

So I had my original fan clutch replaced. One day it started to sound like a bus when ever I drove, and the noise of the fan spinning would increase and decrease with the RPMs.

Fast forward to after my mechanic replaced the fan clutch with an OEM fan clutch, and it continues to make that same sound that it did before, prior to replacing the fan clutch. My mechanic is saying that this is how it is suppose to sound, and he is saying that my fan clutch is working as it should.

I don't necessarily agree. Prior to my old fan clutch making the bus-like sound, it was quiet, and could never be heard as RPMs increased and decreased. He is saying I didn't hear it because my old fan clutch was not working.

With this logic, it would mean my old fan clutch didn't work and then worked suddenly one day because it makes the same noise my current one does.

I have read and seen on many videos that the noise should go away after this part is replaced. Is my new fan clutch defective, or is it behaving as it should?