get somebody's motor running

Then she climbed out of the car and left the motor running.

I kept the motor running, in case the family Sachs suddenly came home.

"Keep the motor running, no matter how long it takes."

Jack stopped his car but left the motor running, taking it all in.

She stopped at the exit to the lot, the motor running.

I sat for a while with the motor running, and looked.

In most cases the speed must be changed with the motor running.

I pulled to a stop in front of the big house, but left the motor running.

John was there, his car out front with the motor running.

He backed up and turned in, but left the motor running.