Hello! I hope you are doing well. I am experiencing a diesel-engine-like sound when accelerating lightly on my ‘08 Civic Hybrid. I’m eagerly curious to know if anyone else has experienced this rattle before and, if so, what causes it, and how to fix it.

-It’s not the heat shield nor anything obvious, so far.
-The rattle speeds up and slows down with engine rpm, but with a slight delay.
-Not present at idle, but very loud during gentle, mild acceleration, then gets louder up until 2-3k and then stops.
-Seems to stop when more torque is produced.
-Doesn’t sound when revving when the car is stopped.

I’ve edited the recording to clean up background, wind, etc for clarity. It’s from the drivers seat and the sound is being bounced off of nearby fences and houses. I was traveling up a slight hill at 5-7 mph. Notice the sound cutoff as soon as I press the pedal sharply.

No CE lights or codes, just over 227.000km (~141,000 mi).

For those of you taking the time to listen, I greatly value your time and input. Thanks!

 

I hear something similar during light acceleration in my 06 HCH with 220,000 miles.
I assume its the sound of a valve, piston pin, or rod cap tapping.
Mines def not as loud as yours tho. Like i dont think i would be able to capture a recording of it.