Basically, Amtrak's "state of good repair" has gone to hell in a handbasket, and engines have been failing left and right this past week. Train 51 was terminated due to a problem with its locomotive (shelled wheels). Train 58 had bad engine problems the other day.
Even the Hiawatha has had some engine problems. See the report I'm about to post in the trip reports section for the latest Hiawatha debacle.