How long does an oil film stay on engine parts after shutdown

[OVERKILL]

I once helped install a junkyard engine in an old VW Scirocco using an engine that had sat in a junkyard for 11 years. The outside of the engine wasn’t very pretty but there was no visible rust inside and everything still had a coating of oil. After that I figured any engine is going to survive sitting for several weeks or months.

That's been my experience with old marine engines as well.

 

[Slow Car Sport Mode]

So the oil is going to stay costing things, no matter what kind it is, is what I am getting?

 

[Silver]

That said, the worst thing you can do on a infrequently run engine, is start it and let it run for a few minutes "to cycle the oil" then shut it off. This won't run long enough to achieve operating temperature, so it won't vaporize condensation and it will only create more combustion byproducts to wreak their havoc on the engine internals. If you run the engine, run it long enough to fully warm up and reach operating temperature, on an actual duty cycle moving the car, not just idling.

I reached this conclusion too, up to the point where the oil film starts to get dangerously thin, if it does. I considered internal parts starting to form a thin layer of rust or some other harmful coating but I don't think that would happen? I don't know the answer to either of these exceptions but figure it's longer than the few months between when I might drive my one vehicle that sits. Before that time, you're just throwing in a needless cold start!

 

[celicaxx]

I read here in the aviation section that some plane owners still prefer conventional oil for aircraft engines over synthetic because conventional sits on parts longer when in storage, etc. Don't know if it's true, but an interesting thought nonetheless.

 

[alcyon]

I think intelligent molecules follow the chain of command ... If they are told to stay up there, they will.

I am gonna try to get them to solve mathematical equations for me...