0

Last year I ended up having to replace my alternator "out of the blue", by which I mean I wasn't aware it needed replacing until my car wouldn't start and also wasn't aware that alternators have a lifespan not necessarily equal to life of the car. Similarly, my neighbor had his timing belt go out at a really inconvenient time (isn't it always) without realizing this is something that gets serviced/replace before it fails, not after.

So my question is: are there there other items like this that need replacing during during life of car but fail catastrophically and usually without warning or symptom? e.g. A battery needs replacing but one usually knows it is getting to that point and it is also easily replaced, so it would not qualify as an answer to this question.

Main reason I ask is this: I drive up to Salt Lake City from south border every year and a lot of it is through barren no man's land with spotty cell phone reception. Had my alternator chosen to fail there, it would have been a true catastrophe. So what other things like that do car owners typically need to be thinking about?

If there is a better title for this question I am open to suggestion.

AA040371
  • 455
  • 4
  • 11
  • 3
    I'm of the "opinion" this question would not be answerable, even as honorable as it is. The reason I say this is, the maintenance items like a battery or timing belt, are meant to be changed on a regular basis to prevent bigger items from going bad. By changing these things out, you are prolonging the life of the big ticket items. Unfortunately, things like alternators don't have a "typical" lifespan. They are mechanical and therefore will not run for ever. Murphy will always peak his head at the most inopportune time and parts will fail. There are warning signs, but you have to pay attention. – Pᴀᴜʟsᴛᴇʀ2 Oct 17 '22 at 13:33
  • 1
    It would probably make more sense to invest in a satellite phone than on changing car parts by suspicion. – Martin Oct 17 '22 at 13:42
  • I understand if it gets closed. BUT, per OP, if someone were to ask me now "what are items with a known lifespan less than that of the car that might fail catastrophically?" I'd answer "timing belts and alternators" and suggest they do some research. e.g. I looked up alrantor lifespan and it said "Generally speaking, you can expect your car alternator to last anywhere between 40,000 and 100,000 miles." Had I known this I would have replaced my alternator at 100K (it failed at about 115K). But I get the semi vagueness of the question. – AA040371 Oct 17 '22 at 17:46

2 Answers2

1

The answer is: "Just about ANYTHING."

It's really that simple. There is virtually no way of knowing which parts, if any, have hidden defects, were damaged at some point, or have just reached the end of their useful life and will fail.

Obviously there are things like alternators, water pumps, power steering pumps, brakes, filters, spark plugs, wheel bearings, drive shafts, and the like that are often considered "maintenance items".

But just about any component in the engine, transmission, axle gearings, suspension, even the electronics can fail without warning.

The best "insurance" is regular maintenance and paying attention to things. I've noticed that it's not uncommon to get a "feeling" that something is just not right. I'm sure it's some sound or vibration that my mind interprets that way but it causes be to start checking things carefully.

Is there some 100% way to prevent such a failure? Not that I'm aware of! Even commercial airliners and spacecraft, which have extremely stringent (and EXPENSIVE) maintenance and inspection procedures, experience in-service failures, sometimes catastrophic ones.

jwh20
  • 12,092
  • 1
  • 15
  • 25
  • While this is sage advice ... how does it answer the question? – Pᴀᴜʟsᴛᴇʀ2 Oct 17 '22 at 14:23
  • The question: "...are there there other items like this that need replacing during during life of car but fail catastrophically and usually without warning or symptom?" The answer is: "Just about ANYTHING." – jwh20 Oct 17 '22 at 14:31
  • That really isn't an answer. As I stated in comments, this really isn't answerable in the way we should be answering things here on SE. – Pᴀᴜʟsᴛᴇʀ2 Oct 17 '22 at 15:27
  • In that case I OK with voting to close it. – jwh20 Oct 17 '22 at 15:28
  • @jwh20 "Just about ANYTHING.": I disagree. Blinkers fail, but not catastrophically. Power steering might fail, but car is still drivable. Flat tire...change it. U-joint failing? It typically makes a racket first so plenty of warning. etc. I am guessing it's a pretty limited subset that fit the conditions I am suggesting. – AA040371 Oct 17 '22 at 17:51
  • @mblatz01 Are you sure that blinkers can't fail catastrophically? How about there is a fuel leak and fumes have built up in the trunk. One of the turn signal bulbs bursts and ignites the fumes. BOOM! Can't happen? I'm sure it has at some point. – jwh20 Oct 17 '22 at 18:00
1

It's true that alternators have a somewhat limited lifespan. They have rotating electric contacts that need to conduct electricity and rotate at the same time. Those contacts are wearables, and even though they are only used for the magnetizing field, not for the actual produced current, they still have to be capable of conducting great currents and aren't trivial. A hypothetical permanent magnet alternator that would use DC-DC converter after it to adjust voltage to be correct at all engine speeds would be far better. For example hybrid vehicles lack alternator, they have only motor-generators (of the permanent magnet type) and indeed the 12 volt battery is charged through a DC-DC converter. Your battery however has usually enough capacity to drive to a garage should the alternator fail.

Another similar component that may fail is starter motor, because ordinary starter motors aren't beefy enough to be useful in stop-start cars. Maybe the newer integrated starter-generators are better than starter motors and alternators. But they are often driven by a belt, that can fail too.

Everything that's made from rubber degrades as a function of time. This includes seals, gasoline lines, tires, CV joint boots, belts, etc. Water pumps require a seal too and that can fail, as can bearings. Though tires can be monitored so it usually isn't "without any warning", a car with gasoline leak or CV joint grease leaking can be driven for short distances, and a broken seal won't ruin your trip. Broken belt is more catastrophical though, especially if it's the timing belt.

In my experience, in many manual transmissions the synchronizers are prone to wear. However, usually you'd just accept the wear because transmission replacement or overhaul would be so expensive. However, clutch wear is something you can't accept, once it's worn then it's worn. Manual transmission cars are notorious for needing clutch jobs. However, these are gradual not catastrophic.

Anything complex can fail in an expensive manner. So for example today's complex automatic transmissions, whether of the torque converter type or whether of the dual-clutch type, can and do fail. Sometimes catastrophically.

Diesel vehicles are notorious for having lots of easily broken components: fuel injectors, particulate filter, urea injection, etc. And you won't find a modern diesel without turbocharging. Turbochargers can get damaged too. Fortunately, these usually won't ruin your trip although they ruin the state of your bank account.

Power steering racks used to be hydraulically powered, and the seals there eventually fail, leaking power steering fluid everywhere. They won't ruin your trip, though, although it's a real pain to park a car without power steering fluid in it.

Any bearing is prone to needing replacement at some point of time, although many do last acceptably long and give an early warning.

The 12-volt battery isn't as durable as for example typical electric vehicle batteries, so replacement at some point during car lifetime is almost certain. But death can be sudden and it may annoy you if you can't start your car anymore and don't have a spare battery (keeping a spare battery is a poor idea because lead-acid batteries really like full charge, have a limited lifespan and a spare battery would get slowly self-discharged and even if not its limited calendar life would be a problem). So I disagree about your incorrect assessment of 12-volt battery failures not being catastrophical.

Engines wear too. A typical engine in fact may last less than an electric vehicle battery! Sometimes engine failure can be catastrophic, e.g. timing belt snapping or so fast oil leaks (fortunately rare) that you won't have time to stop the engine.

Spark ignition today is fortunately very reliable since we have usually per-cylinder ignition coils, no distributor, and if a spark is disabled from one cylinder it's detected and fuel won't be injected so your catalytic converter won't overheat. However, theoretically the engine control unit could fail. Or its relay -- I once had that happen in a 1989 Opel Vectra. Good ECU but crappy ECU relay.

I'm sure I missed maybe more than half of the most likely components to fail.

juhist
  • 14,547
  • 11
  • 58
  • 98