Do you know what may be causing the annoying amount of shaking the car does? The steering wheel vibrates alot as well

 

Could be something simple like poor alignment, a bad tire, etc.

 

Are the idle rpms too low?

 

so your saying the steering wheel shakes at idle...if thats wat your saying then either your rpms are too low or you could possibly have a motor mount bad.

 

Your subject says car shakes at idle, but you don't give us much information from there. What RPM's are you at with the car in nuetral/park? Does it have any difficulty with power? If your RPM's are lower you might have bad spark plug wires or plugs causing it to run on a three or missfiring. Low RPM could be fuel delivery, spark, or timing.

If your RPM's are normal you might have a bad, or broken motor mount but I would think you would notice that at all speeds. Some more info on when it shakes and what rpm it does it at would be helpfull.

 

RPM's are at about half of 1 mark at idle!

 

What year and model Civic?

Is the check engine light ON?

Try adjusting the idle screw on the throttle body. You might also have a dirty IACV or air filter.

 

What year and how many miles?

You could have a bad motor mount, cylinder pressure imbalance, a plug not firing, idle too low, timing way off, or any combination of those.

 

2000 Civic Ex miles=121,512

 

Is this issue ONLY at idle? Does the carrun just like normal exceptat idle?
DO you have polyurethane motor mount inserts? I do, and I always have a vibration at idle (the steering wheel feels almost like a sewing machine)once the engine reaches operating temp. (RPMs are below 800)and it shakes even more with the A/C on (but it always goes away whenIget the RPMsup above idle). Sometimes when people ride with me (and we're idling somewhere), they say "you probably need plugs and wires because you have a miss"but I tell them no - it's because of the motor mount inserts which make the mounts essentially like a solid mount hence the vibration at idle. Ifyou have them like myself,you have three choices.
1. raise your idle a little (850-1000RPM, but will use more GAS)
2. remove the inserts (back to stock)
3. LIVE with the vibration (what I decided)

At your current mileage I would definitely change out the plugs, wires, cap and rotor, fuel filter, air filter, PCV valve, and set timing: basically a tune up(if you haven't already) and don't forget you should have done the timing belt and water pump at 105k.
If you do not have polyeurethane inserts, then maybe your idle is too low, bad gas, fuel filter, needs tune up, etc. like others have mentioned in this post.