Cold engine sound

[chunalt]

Has anyone had a strange sound from the thermal engine when starting it for the first time (not so cold outside, 16 degrees Celsius), it doesn't run linearly, the noise fluctuates up and down. Most of the time it starts on EV but at some point thermal engine starts. I know that for all brands, the cold engine revs higher on first start, but here the sound fluctuates. No more noise after 10 minutes of driving after warming up. Thanks!


Video here:

 

[DBedford]

Sounds like an aircraft!, Possibly cavitation or a bearing issue!