What is tuktuk noise? Prominent when car's cold

[imhere]

Around 0:22 I rev up the Vitz/Yaris engine, the sound also follows engine revving up.

Then I let it idle and it's prominent again at 0:35.

Please listen: https://streamable.com/z54arx

It's more audible when the car's cold. As you rev up at idle, sound frequency also increases.

The sound either disappears or the intensity reduces a lot when the car's driven and is warm enough. Becomes a bit difficult to hear then.

What could be it?

I've driven around 1500-2000 KM after it started coming up... been okay, haven't noticed issues in drive/power.

[ex-x-fire]

Is that a diesel?

[imhere]

Is that a diesel?

No - petrol. 1 Liter. The 1krfe is noisy..

But this ticking noise is something new, started coming around 2k KM back. When car's cold and idle, follows RPM, disappears or can barely be heard once you drive it and car's warm enough.

[nortonfb]

The appears to remain constant when you rev the motor.
Heat shield?

[BIGTAZ351]

That sounds like a piston broken skirt or connecting rod...top/bottom I don't know. But start looking for new motor...