So, my Dart has a noticeable drivetrain shake when the car idles. You can feel and hear it especially when sitting at a light. 2 months ago when my mechanics checked the compression on my 273, they said one cylinder was reading low compression (I believe around 50-60 psi). I've heard that could be a cause for the shake as technically the engine isn't completely balanced. What other causes could it be from? Bad engine mounts?

Again, this can only be felt at idle? Should I be particularly worried about it? I only drive the car about a 10 mile round trip once every 2-3 weeks or so.

Thanks for your help!