bad engine mounts
Most definitely. Any miss will cause the engine to shake. A vacuum leak will also cause this.
Many things could cause an engine to shake. One, for example, would be low coolant or oil levels.
Bad engine cushions can make the engine shake. bad spark plugs cause malfunction as the car starts running.
a bad engine
Worn motor mounts
possibly a broken or missing engine mount
No, not unless it is so low the engine is overheating.
Engine mounts could be loose or worn.
because that's kind of a big engine
what does idle funny mean? Does the whole car shake? (upper engine mount collapsed) Or does the engine shake/misfire? (Intake manifold gasket)
Maybe its your motor mounts.