obstruct vs put a monkey wrench in the works of

obstruct

verb
  • To get in the way of so as to hide from sight. 

  • To impede, retard, or interfere with; hinder. 

  • To block or fill (a passage) with obstacles or an obstacle. See synonyms at block. 

put a monkey wrench in the works of

How often have the words obstruct and put a monkey wrench in the works of occurred in a corpus of books? (source: Google Ngram Viewer )