Not sure if any of you other EX owners have this occurence, but I hear almost a metallic rasp or heat shield rattle occur when the engine has been warm and is staying above 3500rpm.

I'll back it down to 3000rpm and I'll hear the noise, and it's consistant.

It sounds like a kind of dumb question, but I've owned several Hondas prior and I know what a rattling heat shield sounds like. But I haven't even been underneath my car yet so I don't know what the expletive is going on.

 

spark plug cover?

 

Yep, its your heat shield. You can have someone rev the engine, while you go under and bend the edges or just take the whole thing off. My RSR gave off a similar rattle at 3k RPMS.