Cold Start Rattling Sound

[WMDC35]

At those revs guess is the cam belt is loose & hitting the cover, I can't watch the video at the moment though.

[dbm7]

11 hours ago, TurboTapin said:

Have you gotten under the car to look for anything that can rattle? I bet you it's a heat shield. 

...very much sounds like it ~ my subaru does the same noise & I know it's heat shield lose around CAT doing it...

[MBS206]

Sounds heat shield related. But odd that it does it at that exact RPM.

That RPM is also very close to the cam switch over point coming off idle, and I've had both Subaru, and Toyota's rattling before when they've been having oil getting up to the variable cam control, and always right on the low RPM switch over point.
The Toyota one I've had is mainly just on start up.