Are car engines more prone to failure now?

[MrWorldwide]

I was wondering, are car engines more prone to failure than say 20-30 years ago? Now when I'm talking about failure, I'm talking about the kind of thing that warrants a rebuild rather than a minor break down.

I can't help but notice I hear more about this sort of thing now than I did in the past. Of course, there is far more widespread forum and social media usage than in the past, but I don't think I heard of many engines requiring a rebuild in the past. I personally know two people who have have rebuilds on their own cars very recently.

Engines are obviously running more power power litre than in the past and I think I'd be correct in saying the engineering behind them is getting more complicated. Is the lack of simplicity causing increasing the likelihood of something catastrophic going wrong?

[Fast and Spurious]

Nope

[stevemcs]

I wouldn't say they are much better, a lot of it comes doens to the emissions and all the kit that goes with it.

[MC Bodge]

Modern engines need very little maintenance throughout their lifetime. Oil changes, filters, spark plugs at long intervals, timing belts ....and that's pretty much it.

There are some that have known weak points, but many failures are down to people not doing the (minimal) maintenance correctly.

I suspect that cars are more reliable than they were 30-40 years ago, although possibly no more reliable than they were 15-20 years ago?

[SlimJim16v]

Porche - bore score and IMS bearing.
Peugeot/MINI/BMW - timing chains.
Must be more.

[stevemcs]

SlimJim16v said:

Porche - bore score and IMS bearing.
Peugeot/MINI/BMW - timing chains.
Must be more.

JLR ingenium timing chains
BMW N47 chains
Ford Eco boost and Eco blue wet belts
PSA 1.0/1.2 Wet belts
JLR 3.0 Bearings
VAG 3.0 petrol and diesel chains, various engine bits
Nissan 1.2 thermostats

[Hoofy]

DB9 and Gallardo cat sucking.

[wst]

Depends on the framing of the question.

We demand more of car engines now - cleaner running (no lead to help with knocking, fewer particulate or toxic emissions, etc), more power per litre or kg (or both), better fuel economy - so in that sense most older engines, being unable to meet those requirements at all, automatically have already failed before we even get out of the gate.

Of course, to achieve those things requires both more components (which can be interpreted as "more things to go wrong"), and more precise controlling of what is happening in those engines ("More things to do wrong" again), and more signs that something is going wrong before the stage of blowing sparks or smoke out of the exhaust etc.

So. Yes. Or no. Or maybe, depending on other things that I haven't thought about here.

[mintmansam]

I think it depends, but I’ve never known a car engine fail due to normal driving

I’ve seen engines fail from oil starvation due to no baffles in the sump on a track and money shifting, but beyond that they seem reliable except for those well known issues

I have a duratec which at around 100,000 wears out its oil control rings, it still runs but I think 90-95% of people would scrap the car based on this. I wouldn’t strictly call it a failure though

What I have noticed working on older cars, is if something fails eg a TPS, you can unplug it and the car will still run. A modern car would likely flash and bong. Every additional component obviously increases the chance of failure

I think it’s more to do with the bits supporting the engine, most engines are infact old designs, ie the castings of the block. I think the modern ford engines are boosted duratec and they are mid 2000s Mazda based engines. Obviously that’s a crude simplification

I guess with data comes refinement and less over engineering so in some senses they may not be as able to be tuned to the nth degree as before

[Mr Tidy]

stevemcs said:

JLR ingenium timing chains
BMW N47 chains
Ford Eco boost and Eco blue wet belts
PSA 1.0/1.2 Wet belts
JLR 3.0 Bearings
VAG 3.0 petrol and diesel chains, various engine bits
Nissan 1.2 thermostats

I'd add BMW N53 and N54 High pressure Fuel Pump and Injector issues to the list. And the N53 Direct Injection engine can suffer from coked up inlet manifolds.

Countless diesels suffer from DPF problems, but that's because the tax regime made them appealing so people bought them without realising how they used their car wouldn't allow the DPF to regenerate.

[119]

Mr Tidy said:

stevemcs said:

JLR ingenium timing chains
BMW N47 chains
Ford Eco boost and Eco blue wet belts
PSA 1.0/1.2 Wet belts
JLR 3.0 Bearings
VAG 3.0 petrol and diesel chains, various engine bits
Nissan 1.2 thermostats

I'd add BMW N53 and N54 High pressure Fuel Pump and Injector issues to the list. And the N53 Direct Injection engine can suffer from coked up inlet manifolds.

Countless diesels suffer from DPF problems, but that's because the tax regime made them appealing so people bought them without realising how they used their car wouldn't allow the DPF to regenerate.

Would a duff DPF require a complete engine rebuild?

[vikingaero]

Manufacturers are increasingly using plastic parts in many engines. Fine in the period up to the end of the warranty but not after that - examples BMW swirl flaps.

One engine that is utter pants is the N14 MINI engine also used in Pug 208 and Citroen DS3. This engine has killed off many of the French cars and it's only the cult following in the MINIs that has kept them going. Utter garbage despite people saying that they "just need extra maintenance". I've seen many 40k engines run poorly and 60k examples on their deathbed.

That said engine sharing is more common these days and a design or longevity fault is likely to affect more cars.

[Giantt]

Could the actual question be,do people do less preventative maintenance or are more careless with cars?
Relying on sensors to tell you when engine oil needed as opposed to regular checking by dipstick ?

[RedWhiteMonkey]

The increase in the ability to mass produce at much more accurate tolerances with the last 20 years means that engines are much more precisely engineered and assembled. This equates to less failure, other than flat tyres or idiots who manage to run out of fuel I rarely see a broken down car these days, it was a fairly common sight 20 years ago.

[mikey_b]

RedWhiteMonkey said:

The increase in the ability to mass produce at much more accurate tolerances with the last 20 years means that engines are much more precisely engineered and assembled. This equates to less failure, other than flat tyres or idiots who manage to run out of fuel I rarely see a broken down car these days, it was a fairly common sight 20 years ago.

This is true. Also true is that there are millions more cars on the roads than 20 years ago, yet you still don't see many broken down. Cars are vastly more reliable than they used to be - in fact I think the reason that the inherent faults in a few engines stand out so much is precisely because such things are quite rare nowadays. Plus, of course, social media means that if half a dozen people get a similar fault, then it automatically becomes a disastrous weak spot in the car which everyone else will suffer from in a matter of weeks, and that model of car should be avoided at all costs.

[AlexGSi2000]

I would say there was definitely a "sweet spot" starting around the late 90s until about 2004.
I say this because it was before the requirements of EGR/DPF's and very stringent EURO requirements.

I think modern engine design (the core block, internals.etc) are good - its usually emissions based equipment / requirements that end up causing "failures"

I agree lower emissions and the EURO requirements are good, however in order to do this - its usually at the sacrifice of something else.

For example, I have read about a few modern Audi diesel top end failures (mainly V engines), a few who have worked on these engines think its caused by the variable oil pump not supplying enough pressure to the top end - to reduce drag/parasitic loss from the pump. So they are advising oil pump "maps" to increase the pressure.

EGRs can load engines with soot - reducing the overall effectiveness of the oil.
Extended oil drain intervals / less oil capacity - fine for the first owner or to clear the warranty period, but an issue 10 years down the line.

Like I say, I think the core of modern engines are fine - in my opinion its emissions requirement actions that sacrifice the longevity.

I remember loads of Fords that got scrapped because of corrosion issues but had perfectly good engines - MK5 Fiesta / Puma springs to mind.

[stu67]

Absolutely more reliable

I'm old enough to remember the 70's, not a weekend went by without my dear dad fixing something on the family car, and these were not some old bangers.
As I get older I'm constantly amazed at how far auto engineering has come, the fact that in theory you could probably drive a car 100k without lifting the bonnet is frankly astonishing. Cars from the 50's to 80's were generally dead by 80k even with constant maintenance.

[Tiglon]

I've yet to experience an engine failure in 20 years of driving. And most of that has been spent driving cheap sheds with no maintenance, no servicing.

I've also done 25k miles in the above-mentioned N54, and had no more issues than ignition coils. Even the engines with bad reputations on the Internet are not as troublesome as some will have you believe.

It's just social media (and other media) highlighting problems more easily than in the past.

[ferret50]

Older vehicles usually needed a 'de-coke' every 30-50k miles and a full re-build at 70-100k miles. When did you need a 'de-coke' last?

[Roger Irrelevant]

Fast and Spurious said:

Nope

/thread. There is quite a lot of data out there showing that both the average age and the average life of cars in the UK has increased steadily for at least 30 years. Now, that's obviously not exactly the same thing as engines being more reliable but it's a pretty good proxy for it. I.e. if it were true that modern engines are more prone to full-scale breakdowns it would be very difficult for the average life of a car to keep rising, especially in the UK where used cars aren't worth as much as in lots of other countries so get written off at the drop of a hat. Yes you can point to particular engines with known issues, but to a large extent it's only because modern engines are so good that these things become a thing. It's not that long ago that a run-of-the-mill engine with 50k miles on it would be seen as on borrowed time anyway. Nowadays a 50k mile engine being seen as a risk because of bore-scoring/dodgy timing chains etc is very much the exception.