Chosen Solution
I just got this MacBook pro today and was wiping the hard drive and updating it to the latest macOS. I ended up tilting the MacBook, notch to open lid facing up towards the sky and all a sudden this very loud, awful sound starting coming from the body of the mac. It’s hard to describe but it sounded like very bad grinding, like the fan trying to crunch metal or something. Immediately put the mac back to normal position and it stopped within 10 seconds. I then tried to replicate the issue and the same thing happened this time stopped within 20 seconds. This all happened while the software update was happening. The reason I tilted it in the first place was to listen to how hard the fans were going. The keyboard and trackpad also don’t work if that matters, I presume it to be a bad trackpad cable. Any ideas why it’s sounding like this? Edit 1: changed to make more clear
For the grinding sound, the problem was a lose screw floating around the inside of the MacBook and getting into the fan. Concerning, it was a black Penelope screw. It seems to be missing from the top right corner on a piece that helps secure the hinge. As for the trackpad and keyboard, the problem was a bad trackpad cable. A replacement cable fixed both.
Sounds like you have a few problems! First the grinding noise sounds like your fans are scrapping there frames. This is often a sign of dust and grit that has collected internally. You’ll need to pop off the bottom cover and using a soft small pain brush dust off the case parts, fans and logic board and a can of can’ed air to blow the debris away with a few short blasts. The keyboard issue could be a few different things. With the cover removed inspect the logic board for staining and corrosion damage. I would carefully remove the logic board to check the back side as a liquid spill would have likely damaged that side MacBook Pro 13" Retina Display Early 2015 Logic Board Replacement Use the guide and replacement part images as a reference on what your logic board should look like. Replacing the keyboard cable is a bt more involved as its stuck under the battery. Replacing the trackpad cable won’t fix the keyboard.
