every engine GM makes in every assembly plant they have is run in on a propane test stand before it leaves station. I read this post on a GM financial board. I guess what they're saying is the engine is "turned over" by a propane source w/o actually staring the engine. Something about a vibration check. Is this common practice at all auto plants or just specific to GM?

 

Hey Tom,
I dont know the answer to your question, but, would say if they are using Propane they are burning it. If they were just spinning the engine up, compressed air would be much cheaper. And I imagine they use propane due to the clean burning characteristics.

Good question

 

Looks like Ford runs them also!

"Sophisticated computer-aided engineering tools have enabled engineers to tune out unwanted sound and vibration in the engine block, while computer-aided manufacturing tools allow them to pre-run assembly lines, to ensure the most efficient manufacturing processes. At Ford�s Livonia, Mich., transmission facilities � the worldwide �center of excellence� for Ford Motor Company automatic transmission development and testing � engineers use one of the world�s most powerful X-ray machines to examine engines and transmissions to ensure quality. "