One channel is mostly teardowns of different busted car engines, and as those are essentially all postmortem operations, they play out like murder mysteries as different parts of the engine face varying degrees of damage from whatever went wrong (oil starvation/clogging typically, sometimes hydrolock or more exotic combustion failures). Apart from absorbing some small amount of understanding of how internal combustion engines work, the need for regular oil changes and inspections has been impressed on me about 20x.