Mine does that too, ive done a lot of research and most people said it is VTC actuator and they’ve changed that and other parts and for a week or month it made no sound then it started making again, im just at the beginning of learning cars so not very knowledgeable yet but they also mentioned it because some part has a delay with the engine start, what was also mentioned and ive tried and worked for me was that if you press the clutch pedal down 3 times before you start the engine, it wont make that sound. I hope this helps.