whenever my cars warmed up and im just idleing, my car starts to vibrate a lot. when i hit the gas, even just 100rpms, the vibration stops.

just started today
no new mods


any ideas?

also if i turn off things like headlights, defroster, let go of brake, vibration stop for like 2 seconds then start again

 

motor mounts?
maybe try cleaning your iacv and TB.
and adjusting you throtelt cable.

 

wtf?

 

it vibrates at low RPMs and then goes away as you accelerate?

it stops when you mess with electrical stuff because your idle changes with electrical load...so your RPMs go up and vibration goes away until it drops back down...i guess 93prelude615 is saying raise your idle RPM speed?

 

I have energy suspension polyurethane motor mount inserts, and I have a vibration at idle. The vibration kind of feels like a sewing machine. This vibration is ONLY at idle after reaching operating temp.

 

yea its the same as this.

but i think it was the cold weather cuz it was freezin yesterday and now its warmer and it stopped.

 

yep, low idle. at a certain rpm range the motor will hit the chassis' resonant frequency and make it shake like crazy. try opening up the idle set screw slightly and it should go away.

 

Yes sometimes this frequency vibration makes my interior panels rattle and the sunroof sometimes rattles when it's open. Sometimes it drives me nuts..

 

which screw is the idle screw and which way do i turn it to raise the idle a little?

 

it's the really big-looking screw, top-center of the throttle body facing towards the intake pipe. you should unplug the iacv before setting your base idle with the set screw, and should be around 500rpm iirc w/o the iacv and 750rpm with.

 

I hear you about the idle. I had the poly bushings with the balancer shafts disconnected. It was a bit rough at idle, but if the A/C was on at idle.. damn.

 

while adjusting the idle screw should the car be running or off?

 

Running. You should read up the steps to setting base idle. Its not as straight forward as dipicted above.