Chapter 48 warns against certain types of teachers. What kinds of spiritual instructors does the text advise against considering as true Sadgurus?

Chapter 48 of the Shri Sai Satcharitra explicitly warns listeners about teachers who may appear spiritual but lack the essential qualities of a Sadguru. The text advises that wise people do not consider someone a Sadguru merely because they have studied the Vedas, know the six Shastras, or practice techniques like Pranayama. It specifically cautions against those who please audiences with talks about Brahman but have no self-experience, describing their knowledge as "verbally hollow." Furthermore, as Chapter 48 points out, giving mantras without any certainty of when the disciple will see results is another sign of a teacher who is not a true Sadguru.