2016 accord exl coupe 2.4L 4 cylinder.
No check engine light and car seems to be running healthy except for a growling noise that comes in waves during cold idle and upon acceleration at <2k RPMs. Sound doesn’t seem to be coming from serpentine belt, it sounds like it’s coming from the very top of the engine. Video attached. Any ideas?

 

Try using a mechanic's stethoscope to determine the origin of the noise

 

it was the cam chain tensioner.