i had something similar with my s2000. is it a constant vibration kinda like a really loud wwwwaaaaaaaaa? if it is i'll bet its your clutch. mine was. the 4 springs get loose and at certain engine levels i.e about 2-3k rpm and make a proper dodgy sound. don't go to your dealer just go to a decent transmission place and get them to take out your clutch(shouldn't cost much-about £70 in the uk). then if u give the pressure plate a shake you'll hear the springs loosely rattling around, if thats what happens just get a new clutch put in and hey presto. it sounds as loud as it is because the gear box casing acts like a bell housing and amplifies the sound. hope this helps.
- posted
18 years ago