I've got a Civic 1.6 LS 2003 (Si), just more than six months old. Recently it has started rattling "in tune" with the engine. The rattling sound is mid frequency, like something would be loose in/near the engine? The amplitude and frequency seems to vary with the RPM and it seems to come from the mid/right part of the engine bay (low?). It does not sound like a bearing (I'd hear it), it's more like an loose axel rotating with the same rpm as the engine??? The rattling appears especially while accelerating in the first, second and third gears with part throttle. It's not so bad with full throttle (?) and almost inaudible if one is not accelerating the car. Also the rattling sound can not be heard if the car is idling. I'm posting because I can well guess what the dealer service will say: "...oh, it's just normal..." or "...we could not hear anything..." So...Has anyone had similar problems with '03 Civics? Thanks for any input! - Eric