EFS 55-250mm f/4-5.6 IS II goes in and out when in auto focus mode

[SROY]

I recently purchased a EFS 55-250mm f/4-5.6 IS II canon lens. But the moment I attach it to my canon t5i camera and turn it on, it starts going in and out automatically. It stops when I shift to manual focus from auto focus. My other lens of 18-55mm works perfectly fine. Is there anyone else facing the same? Please help me to know if this is because of some setting problems or lens needs to be changed?

[ebiggs1 · Accepted solution]

"... it starts going in and out automatically."

What does that mean? It is trying to focus?  You don't mean it is zooming in and out? If your other lens is working as it should it pretty much tells you this one is faulty.  Doesn't it?