Auto engine rebuilder and diagnostic

I need a person who can diagnose a bad engine in a car or truck. If you think the engine is bad I would like you to specifically tell e what it is that is bad about the engine.

Then I want to know if you can tear apart the engine and repair it. I have some mechanics now who are telling me that every other truck has either a bad engine or a bad transmission.

I think I need an expert to take a look at my vehicles and try to teach me a few things.