We have a 2009 CR-V 4WD that was recently purchased as-is from a Toyota dealer, almost 100k miles. I've changed all the fluids, including switching the oil to Mobil 1 full synthetic and a Honda filter.

From the very beginning, I've noticed a knock/rattle that occurs constantly, whether the engine is cold or warm. I always hear it clearly inside the car while we're driving.

But it only seems to happen when the car is in gear. If it's in park or neutral, the sound seems to go away.

I tried unplugging spark plugs (while in gear) to see if it was one particular cylinder, but the sound seems to go away when I unplug any of the spark plugs (hard to tell with the rough engine).

In this video, the car starts out in park, then switched to reverse, then back to park.

Any ideas about the cause?

Thanks!

 

sounds like the valve lifters need to be adjusted
this is regular manitnece

typically there is little risk with this from what i hear

I think Honda service will do this for like $180