Well, yes an osilliscope is(OR CAN BE)a tool that is used for doing diagnostics.If it is an older machine, I would take it elsewhere for diagnostics.(I am saying older by 18 years old or more).Also look around their shop/place of business to see what it is they work on(types and years).If there is A LOT of junk around, I would suggest going elsewhere.
Ask if you can see the Osilliscope they are referring to.If it says something like Automotive digital engine anaylzer it may be what you need.
Have you done the simple stuff first,like compression test,leak-down test or even put a vacuum guage on it?

Let us know(King for a day grin cool )(Keep asking questions cool )

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