Well ever since I had my S (june of 05) it had this buzzing or rattling sound at around 4-5k when cruising in any gear. It's never gotten anyworse, but it hasnt gone away neither. When I had the differential fluid changed at 30k it was pretty dirty, it was done at a honda dealer, (they used 90w gear oil and no that the dual pump crv fluid will destroy the S2k differential). Well I know have 43k, so I decided to change the gear oil, well, it wasnt that dirty at all and had ver minimal residue on the drain plug, when i say minimal it was a dusting. But the noise is still there, no gear whine that is audible, just this rattling or noise at 4-5k. Obviously It wont do it if I'm at a stop and rev it in neutral. I have no crunching noises and soesnt make any noise when coming to stop or when going from a stop to go.

Im pretty sure the noise is coming from the back of the car and not underneath. I looke dunder the car and made sure nothing was rubbing on the exhaust. It does sound similar to a slight exhaust rattle, that used to plauge the Integra GSR and ITR.

It doesnt howl or whine. Any Ideas would be greatly appreciated

 

I have a 03 as well. My car has about half your mileage and it makes some clunking/rattling noise when I go on and off the gas around those rpm's you mentioned. I was under the impression that noise is normal drivetrain operation. The noise has not cleared up and it has not gotten worse(thank god).

 

[QUOTE=SpaZilla,Feb 5 2006, 11:11 PM]But the noise is still there, no gear whine that is audible, just this rattling or noise at 4-5k.
It doesnt howl or whine.

 

to hear humming with the stock gearset/diff is not very common, and difficult to discern from the other noises the car makes.