How should I address a possible mistake to co-authors in a submitted paper I am co-author of a submitted manuscript. I think I found a mistake in a methodological approach in our paper. But I am not sure if I am right. But if that mistake is really there, then some conclusions in this paper could be changed. It will not invalidate the whole paper, but some parts would have different meaning. 

I already had some arguments on this paper, so I do not want to point some mistakes to my colleagues. I fear that if I will point to this possible mistake, my co-authors will get angry. 

I don't even know when and how should I discuss this issue with co-authors? Some authors are reachable only by email and I don't know if I should ask about this mistake only the main author, or send the email to everybody. Or should I just briefly explain what I mean or send a proper document with explanation why I think I am right?

I am thinking of waiting until review; if reviewers do not point to that mistake I will raise it.

Edit: By mistake, I do not mean that we carried out our method of choice incorrectly; instead, I think we should have chosen a different (potentially more correct) method of analysis.
If you believe there is an issue with a paper you are a co-author of, then you absolutely should discuss it with your co-authors. In most (all?) fields, having read and approved the final manuscript is a necessary condition for authorship of a publication. I assume that you cannot really approve of a manuscript that you suspect has methodological flaws, so you should speak up now. Whether that is best done by emailing everyone or just contacting the lead author depends on a lot of external and contextual factors, so I cannot offer advice there.

Waiting for reviewers to spot the mistake seems like a very bad strategy. After all, what will happen if they don't spot the mistake? Either you bring up the issue after receiving the reviews (which is surely not better than bringing it up now) or you remain silent and become co-author to a paper that may have serious methodological problems.

In the end, if you bring up the issue now, there are three possible outcomes (presumably after some arguments and back-and-forth):


You convince your co-authors that there is an error. Since the paper is already submitted, all authors will have to discuss how they want to handle the issue in that case. This may range from updating the paper with the necessary corrections after receiving the reviews (regardless of whether or not the reviewers found the same issue) to retracting the paper.
Your co-authors convince you that the issue is in fact not important or not an issue at all, which may also help to improve the paper (clarify why x is not an issue in this particular context).
Neither you nor your co-authors are convinced by the others. In that case, you may have to withdraw as an author, painful as that may be.


I would argue that each of these results (even the last one) is preferable to just hoping for peer review to catch the issue you already know is there.

Edit: I missed that the manuscript was already submitted. However, I don't thnk this fundamentally changes things.