Using "andar" for "to function"

Question

I recently came across the usage is andar to mean to function. I attempted to use this in a Mexican context where I didn't want to eat, and attempted to say "My mouth isn't working right now" as "Ya no anda mi boca". This got a good few laughs, and I was corrected to use "funcionar" in place of "andar".

So my question, what is the subtle difference between the two when talking about if something is working or not in this context? Why can I say " No anda mi moto" but not "boca"?

Answer 1

Simply put, 'andar' is only used when referring to something mechanical/a machine. According to the RAE:

• Andar 3. intr. Dicho de un artefacto o de una máquina: Moverse para ejecutar sus funciones.

E.g.: La moto no anda porque está sin combustible.

I suppose it could be translated as 'go', for example: no anda mi coche => my car won't go.

Hopefully that shows why using it for 'boca' etc. wouldn't be right.