Diesel

People who cause a lot of trouble.

Diesel is also one of the characters from Thomas the Tank Engine.

"There's been a diesel running up and down this train, causing all sorts of fucking havoc."
"Yeah, I still feel like there's a diesel lurking about."
"Man, I'm trying to get diesels out of my life, you know?'
"'Cause diesels bluff, they go too far."