That would make absolute sense! If my understanding of the purpose of the secondary air injection pump is correct, then it is normal that I hear it in the morning when the motor is still cold and the combustion is still not good enough to have low emissions, then it goes away after a few minutes because the motor is warm. I don't hear it in the evening leaving from work because the engine is not that cold, given that I live in South Florida hehehe.
I will definitely confirm tomorrow morning.
Am surprised people are saying this humming sound racecar is hearing should not even exist.
Thanks for your input!