I just received this lens new and after using it today with my C100 I notice a bright white/blue spot distinct from flare when the sun is shining from the side and then moving the camera toward the sun. It goes away when there is no bright light source. Pointing the camera at my neighbor's grey wall I can see the spot even when there is no lens flare, it looks strange. It is not a stuck pixel and ABB does not change the presentation, nor does a change in ISO. Is this common with this lens or could this be a flaw with this particular unit? I'm thinking of returning it.

I have shot a lot with the 16-35 II, stills (1DsM3, 5DM3, 1D X) and video (C300), and have never noticed anything like that. Doesn't sound normal.

You could try it on another body. Can you post a frame grab of what you are seeing?

Also, is there a filter on a the lens? Could be an internal reflection from a screw-on filter.

Here is a screen shot. The bright spot is over the street but on further review I suspect it is an example of the 16-35 II's poor flare issue. As I panned over toward the sun the flare was more obvious and included additional flare spots.

Is there a link to the screen shot?

I also have a 16-35 but never noticed any problem like yours. See if you can isolate the problem:
1. Take off the lens. Peer through the back of the lens and look at a low light source such as a lamp. The glass should appear clear.
2. Position the camera on a tripod so you see the maximum flare you describe. Lock the camera down. Without moving the camera body, turn the focus manually. Does the flare rotate with the lens? If yes, then the problem is in your front element. If no, then...
3. Shade the camera and lens with a piece of cardboard, then move it slowly left/right. Check to see if there is a light leak somewhere on the lens barrel itself, between the lens and the body, or between the lens shade and the lens.
4. Try different apertures to see what f-stop maximizes the flare.

Hopefully you'll be able to determine where the flare is coming from and what is causing it.

Here is a screen shot. The bright spot is over the street but on further review I suspect it is an example of the 16-35 II's poor flare issue. As I panned over toward the sun the flare was more obvious and included additional flare spots.

Here is the screenshot. Somehow I did not upload it before. Thanks for the information I will try it this weekend if Wisconsin ever warms up.

For medium-wide lenses thats actually really good flare control. Minimal to no halos, not a lot of contamination otherwise. If your main cause for concern is that singular hotspot in the middle of the frame... then correct it in post. If I got plates that clean on a normal basis I would be damn happy. If this is underneath your standards I would really like to see what glass you have been shooting with beforehand.

Here is the screenshot. Somehow I did not upload it before. Thanks for the information I will try it this weekend if Wisconsin ever warms up.

The flare in that screen grab is *normal and quite well controlled as others have said.

*Assuming it's coming from the sun in the frame. In your original post you said it was visible when pointed at a wall - if that's the case, and it's the same then that could be an issue but that is what you need to test.