I did notice it was an oil burner though. I also noticed that Sheldon "pumped" the throttle--that bit bothered me. o, what railroad did 29 come from?
How did you notice it was an oil burner?
Having not seen the episode...sometimes you do need to push the throttle in and out to get what you need from the engine...Not sure if that's what you mean by "pumping" the throttle.
He was pumping it like a pump handle. Not at all the way an engineman would work a real throttle. In another scene he was "welding" on what appeared to be a big block V-8 automobile motor and calling it "the engine from a diesel locomotive".
I don't know why anyone would expect any degree of accuracy about railroading on a show which uses the character's interest in trains as a means of showing that he's a dufus and a social misfit.
On another episode, while discussing the Napa Valley Wine Train's motive power, it was stated that the locomotive was built by Alcoa [sic]. I won't quibble that the FPA4s aren't pure ALCos but rather an ALCo design built under license by the Montreal Locomotive Works in Canada. But they certainly weren't built by the Aluminum Company of America (Alcoa).
I watch the show for laughs (and because Kaley Cuoco and Melissa Rauch, Penny and Bernadette, are very easy on the eyes) but most of the train references are dumb and borderline insulting to railfans.