i have a vibration that i have no idea whats causing it. it does it at any speed but is most prevelant at idle. when at idle, when you can watch it, the steering wheel moves, the rear view moves and you can hear the door pannels vibrating aginst the doors. also when it vibrates the exhaust is close enough to the trans pan that you can hear it occasionally ping the transmission drain plug. only thing i could possibly think of is a motor mount, but i dont know, i've never had an issue like this. ideas please!?!?!

 

You could have a bad motor mount, but first check whether the idle speed is set to spec as detailed in the service manual. A rough idle may be contributing to the problem.

 

i have to apologize for the bad info i gave. i took a short trip to the store and back and noticed that while driving there is no vibration, it is only when in park or at a stop (idle).

acording to the tach in the car anytime it gets down around where the idle is suppost to be is when i pic up the vibration. the manual says idle should be at the first white line after 0 which is 500rpm. anytime i get below about 800+/- 50 i pick up the vib.

 

To ensure accuracy, you should measure rpm with a digital tachometer or scan tool.

You may want to:
1) Clean the IACV (see DIY) and adjust the idle speed.
2) Adjust the throttle cable and clean the throttle body.
3) Do a Seafoam treatment (see DIY).

Is the CEL ON?

 

Right, don't trust the dash tach to measure idle speed accurately.

Anyway 500 is too low, it's going to shake. I think the correct speed is 750 rpm or 850 with the A/C on. This speed is set by the ECU, you can't adjust it, but if something is wrong the ECU won't be able to bring the idle into control.

 

Yeah, let me share my anecdotal experience for getting the smoothest idle on my 97 Civic (D16Y7, 5-speed). The service manual states that the idle should be 670 rpm without load and 810 rpm with load (the A/C ON and the blower running full blast). Initially, I set the the idle screw at the lowest possible setting that would achieve each rpm set point. However, there was a delay in achieving the set point and even over time there were still minor rpm fluctuations, resulting in a modestly rough idle. I then repeated the process but, this time, I adjusted the idle screw where the idle would reach both the "no load" and "load" rpm set point most rapidly without over shooting. This resulted in a smooth idle under both conditions.

 

CEL is not on, BUT i have an aftermarket exhause (header back) and i got one of those spacer for the o2 sensor and ever since i erased the code after puting it in the light hasnt come back on. will check the idle rpm, and will look into seafoam.