Has anyone ever put sawdust in an auto engine?

While there's no record of anyone *intentionally* putting sawdust into an automobile engine in a way that's meant to be part of its operation, it's highly likely sawdust has ended up in engines accidentally. Dust and debris are common contaminants in the air, and sawdust is no exception, especially for people who work with wood or live near sawmills.

Putting sawdust into an engine intentionally would be incredibly damaging. It's not a lubricant, and would act as an abrasive, causing severe and immediate damage to moving parts. The engine would likely seize up very quickly.

So the answer is: probably accidentally, yes. Intentionally, no (at least not with the intention of having it function as part of the engine's operation).