What is this noise?

GEN 4 4RUNNER Urban Runner
Recently rebuilt engine
Coils and plugs are good
All cylinder pressures are good (so valves and lifters should be good)
No Codes except random misfires every few hundred miles but only on starts. Starts are pretty rough unless I give it a little punch on the gas pedal.
Sounds like timing chain rattle or VVT timing chain but again, no codes.
Also this noise doesn't come out until the engine is warm.

Youtube video here

 

https://www.youtube.com/shorts/KCvX-o8NuWA

 

Welcome

 

Sounds a lot like the timing chain tensioner is not bolted down, and the timing chain and tensioner are both flapping around in there.
Does the sound go away when you rev it up? This puts tension against the chain and pulls it tight while the chain is under load.

 

No the sound gets faster as the engine revs

 

what I learn from TCCN that sound will continue without any harm unless you change VVTi gear unit for new, not affected by high mileage. something inside VVTi unit give way, not harm and VVTi work OK - no codes. call it "slapping sound" and live with it. do not tear engine apart until you have codes

 

Thank you. My mechanic was very reticent to open in up. I may open the tensioner window to check the timing chain but this engine was just rebuilt. May go back to the guy who sold me the rebuilt engine but he's a total scrub.

 

That is not acceptable for a “rebuilt” engine (which should have come with a warranty)

 

Welcome from Wisconsin!