Would I lose my warranty if I open the iPhone?

Hi, how are you all?

My iPhone fell in the water about a week ago; it is perfectly working now, but it has some problems since before it fell in the water.

My idea is open it to see if the water indicators are colores but I am afraid I could lose the warranty; is there anyway they can find out I open it?

I was thinking I should have a look at the logic board and see if there is corrosion, but again, I am afraid my cellphone company/apple will catch me.

What do you think?

Thanks.

-C