A
AC Question
It happens more often when im charging it but sometimes it will happen when i am not, so perhaps it has to do with the battery ? I have no clue.
Gurgling? I'm wondering if it's a notification of some kind given that you get the vibration with it. Usually, if the thing notifies you, the pull-down menu will tell you what the notification is. Failing that, you may have a notification reminder that is persistent that you need to turn off.
So, if the pull-down doesn't tell you anything useful, have a look in settings... Accessabilities... Notifications reminder for any ongoing alerts... If you can't find anything, come back and tell us and we'll troubleshoot some more....