Updated: I mean, of course, "fire" in the metaphorical sense, not in the "march into his office and yell 'You're fired!'" sense.
What should you do when a mentor is giving you what you think is bad advice? What should you do when you start to feel like your mentoring relationship is causing more harm than good?
I'm going through this situation right now, and I'll be honest---I'm struggling mightily with it. This person is a senior professor in my department that I sort of hand-picked to be my mentor. I've certainly had some very productive conversations with him in the past, and I like him a great deal as a person. Lately, though, I am less and less impressed with our interactions.
I often leave our conversations feeling way more stressed out and anxious than I did at the start. He's been giving me "advice" about my review that is troublesome in some respects and, according to people I've talked to outside of my department, downright wrong in others. He doesn't actively discourage my work, but neither does he encourage it with the same enthusiasm that he used to---sometimes I really feel, after talking with him, that whatever I'm trying to do is inherently flawed. It's kind of making me gun-shy about taking risks, especially in the classroom---and that's totally unnatural for me.
What's perhaps equally troubling is that, beyond this person, there's really no one else that I trust as a mentor in my department. So, if I "fire" this person, I really don't have any other good options, and I'll feel even more out in left field than I normally do. (Of course, that's not really a change from how I feel now *with* a mentor.) I have some great mentors outside my department, which have been absolute godsends, but I sort of feel like something's wrong if there's no one I trust inside the department. After all, that kind of mentoring is important to navigating department culture, which we all know is really important for gaining tenure ("collegiality").
I'm tempted to wait this one out. Perhaps this is just a personality quirk that is coming to light. Perhaps my mentor is just having a bad week/month and is inadvertently taking it out on me. Perhaps this is my mentor's way of letting me know that I'm not going to pass my review, and he's starting to distance himself from me. (This last scenario keeps me up nights, lately.) Or perhaps this is just me realizing that I need a different kind of mentoring than this person can provide, and that it really is time to move on.