If I'm hearing you right, the console is constantly trying to eject the disc while the button is not being pressed. A solution you may want to consider is removing the button entirely (I'm pretty sure you can still eject the disc from the Wii menu). Try removing the faceplate to get to the button and remove it, to see if that fixes the problem or at the very least to clean out any broken plastic components that may still be in there. Wii Faceplate
Here's the part: Nintendo Wii Faceplate
EDIT: Whoops! Turns out you can't eject the disc from the Wii Menu. I tried through a whole episode of Seinfeld.