because it only appears in one scene, not the entire movie.
But you gotta love that roaring sound of that engine because its to die for.
It sounds like a Detroit 6V92TA mostly found on city and tour buses from the 80's and 90's and some cab over engine trucks such as this Peterbilt 352 right here.
Gotta love those detroit 2 stroke diesel engines because they know how to rumble specially the V8s.