1
general::
Phrase(s): find fault (with someone or something)
to find things wrong with someone or something. • We were unable to find fault with his arguments. • Sally’s father was always finding fault with her.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Criticize, express dissatisfaction with, as in She was a difficult traveling companion, constantly finding fault with the hotel, meal service, and tour guides. [Mid-1500s]
American Heritage Idioms