Cotty,where was that?(Edit-Obviously in the sight!) I made the edges coplanar, put it didn't closed. (Edit I have had another go on it, and it worked ...)
I wonder sometimes, how can one achieve such a faulty model.
Since there are some other open faces that won't close I would advice you to remodel the part entirely. Since it is a symmetric model, I would use follow me tool to recreate it.
part needed bottom cleared-fixed.jpg