integra vibrating while sitting there

I own a 94 integra gsr w/ 132k miles on it, when I am sitting at a light the car makes a low pitch noise and vibrates not really bad but it is noticeble, then when i rev it up at all or accelerate it the noise/vibration are gone. I have heard that one of my motor mounts might be missing the rubber that prevents the vibration. Is this the probable cause of the vibration and noise?

does the car have any mods? it could be your lower torque mounts going bad or the mount bolts could be loose

bad mounts is a possibility also as you said

bad mounts, bad spark plugs, bad wires.....IACV....idk!

How is your idle?, if it is good id say a motor mount. I got 136K miles on my car and mine were shot at 100K. They become cracked and eventually just fall apart.

It is completely stock, it idles fine, when cold around 1500 RPM then when warmer 900 - 1000 RPM, Is it hard to replace the motor mounts?

it sounds like bad motor mounts to me

its not that difficult as long as you can safely support the motor and trans