Err, not to quote myself, but if your Escort doesn't have a rediculous shake when idling then my comment sounds completely dickish. Just thought i'd clarify, lol.
Mine really only does that when the electric fans kick on and pull the motor down to 500 to 600 rpms. Majority of the time i idle around 800 to 1000 rpms and i dont have that rediculous shaking going on.