I would like to start out by saying that I used the search function and read through quite a few threads and none had answers.

Vehicle: 1990 Civic Sedan 1.6 Auto

I just picked this vehicle up from an elderly family friend for $400 and he drove it everywhere. Not sure if he ever noticed it before he passed but while in Park or Drive while stopped the vehicle starts vibrating the dash and steering wheel and gets loud like it has an idle issue (Loud Vibration from Passenger side) but not a sound like the rpms are changing. The RPM gauge holds steady at about 750 to 800. No fluctuation. As soon as you give it a bit of gas it goes away. No CEL.

Are the gauges fairly accurate in these?
Anybody ran into this before and figured it out?

I thought about adjusting the idle but it’s sitting right where it is supposed to. Any help would be appreciated. It’ll be a good car once I find a drivers side tail light and the problem is solved.

 

My 1990 Civic Hatch, also automatic, did this. I bought it with a partially stripped interior, but there was always a weird vibration at idle when stopped also. I cleaned out my IACV and it smoothed out my idle a bit. My 4 speed doesn't do this, so im not sure if it has something to do with the transmission? Both of my cars have around 220,000 miles.

 

I will have to try that. Just trying to get it to where I can enjoy it until I can afford the B18C swap.

 

Is the idle actually rough, or are you just concerned with the chassis vibration at idle?

Most of the Civics from the 80's and 90's will have inaccurate tachometers due to the age of the capacitors on the tachometer circuit board. Replacement of the capacitors (and recalibration of the tachometer) is possible, however. If you have access to an external tachometer, you could connect it and compare against what the dash tachometer is saying.

 

May be time to change engine mounts? Our cars are old, and the interior bits are going to rattle to some extent. Maybe a video would help identify it.

 

Here is a quick sound of what I’m hearing. Idle stays steady. I cleaned the dirty IACV and this was after.

 

so unofficially I gave up. It’s at a shop. Good news/Bad news I guess. So they said a mount collapsed (Praying this fixes it) but I got home and was looking through Facebook EF group and there was a guy complaining about the same issues. Said he had new mounts on his. Ironically him and 5 others all commenting are having the same issues. ALL OF US ARE AUTOMATIC!!! The others have all replaced mounts so I think it’s something with the Transmission

 

Best of luck! BTW if you posted a video / sound clip it never showed here.

Have you tried listening around the engine bay while it's idling and shaking?

 

I did. And honestly it sounds 10 times worse in the car. Apparently it’s not letting me post videos.

Now I just have to figure out this rear disc swap issue.