Vibration on idle - 2001 Accord

My 2001 Accord LX 4 cyl., purchased in May of 2001, vibrates at quite a
low frequency, in gear, when fully warmed up at about 700 rpm. The
accompanying sound is quite loud with all windows closed - the cab
appears to be resonant at this sound frequency and the sound is hard on
the ears. It is not nearly as noticeable with the windows open and also
somewhat less bothersome when in neutral. My dealer has checked out the
engine mounts and claims all 4 cyl. Accords do this. Anyone out there
have a similar problem ? or know of a fix ?

Al Oldfield

 

Every 4 banger I've ever been in does this to some degree. It's simply
natural that an engine with so few cylinders is going to idle rough at the
same RPM a typical V8 would idle at. 4 bangers have nice even 180* pulses,
but that doesn't make up for the fact that they can't happen as often as a
V8 at the same RPM. I had the 289 in my '67 Galaxie idling silky smooth at
~500 RPM hot and 550 RPM cold. It would idle a good bit lower than that but
would shake, and 500 RPM is already a bit lower than where it was from the
factory. My Prelude idles rough/vibrates at 600-700 RPM, but give it a
little gas to bring it to 1000 RPM and it smoothes out. Either up your idle
and get a tiny bit worse mileage and harsher shifting into gear (since
you've got an automatic) or try to ignore it. I wonder if you could get
softer engine mounts to dampen more of the vibrations, or perhaps some
dyna-mat or similar sound absorber/deadener?

Cory