Hello everyone! I'm new here.

My 96 Stratus has about 112k miles (very low for its age) and it idles roughly. The RPM when idling is about 700-750. The rough idle isn't truly a ROUGH one, but my steering wheel shakes badly (I've been told the rear engine mount is busted) and the RPM changes from 700 to 600 which makes the steering wheel shake even more!

Is the broken mount harmful to the engine? Is it the reason my steering wheel shakes? And why does my engine occasionally go to 600 RPM?

Thanks!