ugugii

1999 S2000, 145k km approximate, engine rebuilt approx 130km (mechanic said everything looked really nice and clean inside, no issues) - Australia

Edit: Video with sound uploaded to reddit due to difficulty uploading via attachments: https://v.redd.it/vqk5etmlnme31

I noticed when cruising around my neighbourhood that the engine was sounding a bit off, so I pulled over to the side fairly quickly.

When idling (sitting around 1k rpm) noticed this clicking sound. Lucky I was very close to home when i noticed and got it back into the garage without issue!
When the engine is cold, it sounds normal but as it warms up it starts clicking when the temp gauge is at 2 bars.

I've attached a video of the sound with very light revving. Sounds similar to the TCT clicking sound I've heard from similar videos across the internet.

Wanted to ask if you gurus can identify this or if there's anything I'm missing?

Edit: Unfortunately I've been unable to upload the video due to "token" issues - maybe I'm doing it wrong?
I had uploaded the video to reddit a while ago, hopefully this will suffice!