I have the same problem for mine, and I think it might be that the battery bracket may be pushing up on the screen. My battery bracket was popping up on one side while the other was screwed down and I had trouble screwing both of the the tiny screws in without one popping out. This causes the entire battery bracket to sit at and upward angle and apply pressure on to my screen. This may not be your exact problem but it is worth a try to see if that could be it.
A simple clean might be enough, remove the bottom panel of the laptop and take some compressed air and try to remove and dirt and dust that could be blocking the fans. Once you have tried that turn it on and just load up a quick game and see if it helps. If not then the fans will probably need to be replaced, try to find a teardown and re-assembly video and just watch them take off the fans, then put them back. Hope this helps