Every 7 seconds, my laptop (Predator G3-571) vibrates.

I have had this laptop for 2 years and other than overheating, I haven't had any problems. But out of the blue, earlier today, it started vibrating every few (counted 7) seconds without fail. The vibrating lasts about half a second and sounds just like a phone vibrating. It doesn't change if I turn the fans up or down, and I took it apart to clean them but still nothing changed. It's really odd and I can't find anything about this online, only phones doing it. To be clear, my laptop still works fine, it's just a bit concerning if I have some hardware loose or malfunctioning or something and I don't want to do any damage to it... help please!