Donald J. Trump’s fine-tuned machine has thrown another rod, busted another piston, blown another tire … whatever.

Alex Acosta has resigned as labor secretary amid growing calls for his removal from the Cabinet post. It appears that when he was a federal prosecutor in south Florida, he worked out a sweetheart deal with alleged sex trafficker Jeffrey Epstein, a former friend of Trump and of Bill Clinton.

Epstein got into trouble a few years ago and Acosta worked out some kind of deal that kept Epstein out of the slammer.

It didn’t turn out well. Epstein now faces additional charges relating to allegations that he had sex with underage girls and allegedly recruited them to have sex with other individuals.

Acosta sought to defend himself Thursday. He didn’t do a good job of it, as he obfuscated his way around questions relating to the Epstein deal. He did say that he and the president have a “great” relationship.

Critics weren’t convinced. None other than Fox News analyst Judge Andrew Napolitano, who works for a Trump-friendly news outlet, predicted that Acosta wouldn’t last through the weekend. He was right.

The sleaze factor keeps worsening around the president. Epstein appears to be a bad dude, although Trump has reportedly called him a great guy.

Now we have another Cabinet secretary’s office going dark. How long will it take for Trump to find a permanent individual to run the Labor Department? Or will this one fall into the hands of another “acting” Cabinet boss?

Moreover, I also believe this shouldn’t signal the end of Acosta’s public role in this mess. He needs to sit before a congressional panel and answer questions about why he allowed a deal that kept Epstein out of the slammer in the first place.

If it smells as if something is rotten, there likely is something rotten.