Every thirty seconds or so my laptop fan starts making a horrendous grinding noise. I know it is the fan because the sound comes from where the fan is mounted. It is fixed when i tip the laptop or hit it. But only for thirty seconds. Any permanent fix or reasons this might be happening?
And yes i have tried restarting and shuting down...
Well, it could be that a screw or something is loose in there, or that there is huuuuge dots of dust on your fan.
I recommend that you open up your laptop (From beneath) and remove the dust covering the fan, and check for screws/other material that could be loose.
Also check for breaks in the fan blade itself, it could be flicking off and grinding against something making the sound.
I think you didn't noticed its plates. May be they are touching to the case of laptop. Also use blower to blow out dust particles from the fan, they really annoy. In my PC, dust is major problem that I am facing right now. It rust up my PC fan.
It sounds like something is getting in the way of the fan.I'd do what Byakuya said.