throw a monkey wrench into

throw a monkey wrench in(to) (something)

To disrupt, foil, or cause problems to a plan, activity, or project. Primarily heard in US. We had everything in line for the party, but having the caterer cancel on us at the last minute really threw a monkey wrench into our plans! It'll really throw a monkey wrench in the works if the board decides not to increase our funding for this project.
See also: monkey, throw, wrench

throw a monkey wrench into

Sabotage or frustrate a project or plans, as in The boss threw a monkey wrench into our plans when he said we'd have to work Saturday. This transfer of industrial sabotage-that is, throwing a tool inside machinery-to other subjects dates from the early 1900s.
See also: monkey, throw, wrench
References in periodicals archive ?
will throw a monkey wrench into the media company's announced merger with Tribune Media.
On Single/Single Saturday night at 8 on Cinema One, the housemates played by Shaina Magdayao and Matteo Guidicelli get into yet another squabble when the sexy Tricci returns to throw a monkey wrench into their turbulent relationship.
The Association of American Railroads (AAR) argues that a new braking requirement could throw a monkey wrench into the entire rail transportation network.
The findings throw a monkey wrench into theories about why ostensibly monogamous animals might be inclined to cheat.
Even though we plan and have good procedures in place, something is going to go out of control and throw a monkey wrench into our efforts.
Of course, there were those Nervous Nellies who insisted on pointing out that the economy is still shaky and that the "geopolitical situation" (a euphemism for war on Iraq) might throw a monkey wrench into things.
Mr Ritter said: "What we see now is a bold diplomatic move to derail this headlong rush towards war that exists here in the United States and try to throw a monkey wrench into the machinery of war."
``What we see now is, in addition to a sincere effort, also a bold diplomatic move to derail this headlong rush towards war that exists here in the United States and try to throw a monkey wrench into the machinery of war,'' Mr Ritter told the BBC Radio 4 Today programme.
"Earlier this year I vowed that Americans United would throw a monkey wrench into Pat Robertson's political machine," said Lynn.
Sometimes--in the throes of an Expo In Print deadline when advertorial materials are late and eleventh hour requests for "minor" changes throw a monkey wrench into plans to leave the office while it's still light outside--it's hard to remember the reasons we're here.
But a Republican operative Anna Chennault persuaded the South Vietnamese to throw a monkey wrench into the settlement the weekend before the election.
Bankruptcies, mergers and acquisitions throw a monkey wrench into such plans.
Noting that many newer cancer therapies work by activating killer T-cells to attack tumors, Reisfeld says administering anti-APO-1 in conjunction with these treatments could "throw a monkey wrench into the process."
Commented Lynn, "Last year when the Christian Coalition said it would draft 100,000 churches into its political machine, I vowed that Americans United would throw a monkey wrench into those works.
"Financial and lending institutions, which occupy about a third of New York's office space, appear to have started to cut back on their space requirements, and that trend, if it gains momentum, could throw a monkey wrench into the Midtown recovery.