I generally don't like "broke down engine" scenarios myself, so I would only inflict them on my players in a spirit of schadenfreude or sadism. Most of the "Star Trek" stories where the warp core is breaching, or the ship is turning into a pretzel, or whatever, bore me to tears. However, I did enjoy the "Firefly" episode "Out Of Gas", mainly because it was so low tech.
I've recently been on a "Deadliest Catch" spree. The deep ocean seems about as close to space travel as a civilian can get right now. Here you are in the middle of a vast nothing, on a realatively tiny ship, with sudden death awaiting if you make the wrong move. In a few episodes, mechanical failures will sideline a boat. One recent episode (I'm watching re-runs, so it might have actually been firtst season), the crew head broke down. They tinkered with it, then wrapped it in a plastic garbage bag and got back to work. Everyone wound up using the captain's head. IIRC, that boat was plagued with mechanical problems. I got the impression that regular maintenance was not a high priority, even though it could cost everyone involved money, or even their lives.
Both of the above exemplify a tension I've seen in a lot of Traveller sessions: profit and expediency vs. caution and good sense. Yes, we really should get that fixed. Just one more job... To paraphrase Clausewitz, "Ships are maintained by human beings". Most of the accidents and breakdowns I've seen are a result of negligence, usually brought on by time or money pressure. Willful ignorance and laziness can't be ruled out, either.
To bring it back to the game, some of my players have shown a willful disregard for maintenance and repairs, and refuse to spend any money on new parts, or overhauls, or such. I even offer to elide such things, just assume they spend x amount of time and y amount of credits on upkeep, but nooo. I think they see it as a battle of wills between them and me. How can a referee say no to an oportunity like that? I would give them my most innocent look (a sure sign of trouble) and ask, "Are you sure you want to do that?" then make a great show of rolling the dice and making a note. After a few such warnings, trouble strikes. And if it means their ship gets torn apart by inspectors and decertified, well, they were warned. :devil: