I hear ya. I can tolerate some noise as I understand it’s a nearly 20 year old car, but the grinding was a nuisance and made me believe there was something more serious wrong with the car.

Mine came with a different cap - didn’t look oem and I confirmed that prior to locating. I’ve been told these can come loose, as it happened to a friend of mine and he luckily caught it before it made its way all the way down. Since it’s the OEM cap, I could imagine previous owners dumping the car simply due to the noise - anticipating something more serious, or just not wanting to deal with it. Researching for a bit these cars have many quirks when it comes to acoustics and rattles. Who knows where it’s coming from and isolating the issue can be a black hole.

Mine didn’t sound like a rattle per-se but more like a grind, video captures it quite well. Never felt bouncy but always fairly consistent except upon acceleration. It was pinned in there fairly tight which would explain the difference in our experiences.

 

Wow! Nicely done dwb!

 

The caps rubber gasket gets hard over time, requiring making it tighter and tighter to keep it from spinning loose.

You can buy a new gasket from Honda. Makes a world of difference. Ounce of lost cap prevention.