I've had this honda civic since 2016 and the car was very quiet when I bought it and for the years I've had it. At sometime this year I have noticed a rumbling sound. The sound comes about at 2k rpm coming from a dead stop or a low speed. No sound in neutral , no sound at high speed and no sound in park. When the car does make the sound you can keep the sound happening if you keep it at 2k rpm but I'm not good at replicating the sound. Happens the most when the car has been sitting at an extended period of time. Im about to break down and buy some chasis ears from Amazon to pinpoint where the sound is coming from.

ALSO if anyone has an 8th gen honda civic does your exhaust pipe make a putt putt putt putt sound ?

Here's the sound the vehilce is making , hard to hear on phone video but quite loud in real life.

Might not be able to hear it from the video camera but it's unmistakable while in my car

 

There was a TSB for the 8th gen.

Service Bulletin 06-059 - Buzzing From the Engine at Low RPM

 

I couldn’t hear anything on the video that stands out. If it doesn’t do it at high speeds then I’d probably not worry about it until you notice the sound get worse.
Or try to isolate exactly when it happens, which gears, etc.

 

Have you replaced the CVT transmission fluid? Supposed to do it every 25k miles, since it’s a CVT and not automatic. Can cause rattle issues