The commonly identified rotor vibration root causes and symptom descriptions specific to each cause are summarized in Section 9.8. Chapters 10 and 11 present specific troubleshooting case studies that fall into two of the most frequently identified problem categories and that are drawn from the author’s own troubleshooting experiences. This chapter is more a potpourri of rotating machinery vibration problem topics not readily grouped into a broad generic category, some taken from the author’s own experience.