Honda Engine Makes Rattle at 30mph

I have a CRV 4 cyl 2001 doing just about the same thing. It happens at 2300rpm and sounds like it is coming from beneath the car. A loud rattling at 30, and 55mph when the engine rpm is 2300. Honda dealer hears it and cannot locate the source. It's very annoying. If your mechanic finds it please let me know. Thanks Rick

Sounds exactly like knocking or pre-ignition, AKA pinging.

Simplest fix may be higher octane fuel.

RickaTTic wrote in news: snipped-for-privacy@4ax.com:

Either loose(cracked or rusted) heat shields or a cracked A-pipe weld(IIRC,it's a double walled pipe,the inner weld,of course),the pipe from the header to the catalytic converter.Some of the heat shields can be unbolted and removed.(just don't park in tall grass;fire hazard)

Brian Stell wrote in news:uD4we.509$ snipped-for-privacy@newssvr21.news.prodigy.com:

If he's using the correct octane,he may have a ignition timing problem,advanced or retarded.

Or a loose heat shield.

...

Yes, it could be a sympathetic vibration rattle but there are several things here that make it sound more like pinging than a vibrating part:

The noise appears "when you accelerate to 30" as opposed to "at ... mph when the engine rpm is ...".

and

"Most noticable when going up hill and pressing the gas".

I'm not sure about the 6th gen accord but I know 7th gen has a knock sensor. Supposedly, when there is pinging it detects it and the engine control system should retard the ignition (but my 2005 v6 pings under similar conditions).