1994 Dodge Shadow shaking

1994 Dodge Shadow 4 cyl Automatic 92,200 miles

I have a 1994 dodge shadow automatic. Had new battery and brakes in june of 09. New tires as of jan. This year. New rocker arm and lifter as of last month. Car shakes very strongly when stopped and when driving until I hit 15-20 miles per hour. As long as I am not stopped or driving under 15 miles per hour car drives smoothly. No check engine light on. When it is shaking/vibrating it is loud and the steering wheel along with the dashboard shake (including front passanger side). I was told it might be a vaccum hose. Since I am getting it inspected this weekend I am trying to figure out what is wrong. I get oil changed every 3k miles. Just had that done a few weeks ago too. Any suggestions would be greatly appericated. Thank you!