Sounds like my son took 20 of his marbles, put them in a paint can along with some scrap metal and an old shaver, put that paint can in the "mixer" at the Lowes, recorded the horrible sound, and put that audio track over a picture of your engine shaking about.
Yup...sounds just like mine.
There is a pretty easy to make it sound better. I put earbuds on before putting on 'earmuff' ear protection. Pink Floyd sounds pretty good over the engine track. One Republic is fun. They can mask the sound. FAVORITE way to make the engine sound better has to be Smashing Pumpkins...something about Billy Corgan's voice that is only slightly more irritating than the clatter of a diesel...makes the engine sound great.