N57 longevity

[Baddie]

Hi all.

Considering a 5 Touring / X5 with a 30/35/40d (to replace an aged Landcruiser Amazon 100 series as the family bus and reduced time spent on maintenance…).

Was aware of the timing chain issue (not a problem until v high miles?), but I’m increasingly reading about major bearing/crank issues writing off the engine because the block also gets warped from the heat. This on top of EGR/cooler issues. I can’t see any pattern to the engines affected, even cared-for ones seem to fail; maybe more common in the twin-turbo. Grateful for any experience and info, and recommendation of any specialist who might be able to advise.

[Baddie]

Thank you. Maybe stop-start and the torsional damper are additional factors?

[Baddie]

helix402 said:

Avoid. Why by a car where the engine may fail spectacularly? The consequences of N57 failure can also be fatal. B57 is supposed to be improved.

I’m interested to understand why you say that. I’ve read the thread about the police car that threw a rod through the sump, sadly causing the death of the police officer.

But other cars have also suffered major engine failures, rods through blocks etc, for as long as we’ve had cars. Would you also advise this for the V6 Landies that snap their cranks?

[Baddie]

helix402 said:

My thoughts are that there is a huge variety of used cars available. Why buy one with a key component that may fail, when other more reliable cars are available? Everyone’s attitude to risk varies. As you say, I’m sure lots of N57s don’t break.

Thank you. Not sure there are many cars that would haul lots of stuff long distances in real comfort up to 15-16 yrs old reliably. Thought the F11/15 BMWs would, may be sticking with the 19 yr old Landcruiser.

[Baddie]

Thank you.

[Baddie]

Thank you.

Spoke to a local specialist. He said they see chains going at 60k, depending on maintenance/usage, and recommended replacing at 100k (£3 k engine out job). To do the main bearings as well is more like £4.5k. Then service twice as often as BMW advise.

The twin-turbo is worse. This may be because one of the main bearings appears to be fed from the turbo oil-return, so hotter/thinner oil.

Agree none of the alternatives are better. The “Police BMW Engine Issues” thread is illuminating, both for how hard the cars are used and for how alternatives are mostly even worse.

Edited by Baddie on Thursday 30th May 16:41

[Baddie]

I-am-the-reverend said:

What a shame. Remember when the old E39 530d's just did 200,000 miles with an annual oil change?

What happened to BMW?

Not sure how much is down to engineering / manufacturing. Modern service intervals have a lot to answer for. Every taxi driver I ride with gets frequent oil changes, and their cars rarely seem to have problems, whatever the make, well into 6 figures.

[Baddie]

Wow. What mileage did the 635 have when you got it? Did it have much history before that? Is the rest of the car equally durable?

Agree, buying off an enthusiast is a good option, even privately.

[Baddie]

Thank you, great post.

rottenegg said:

The N57 is a far better engine than the M57 in all the key areas for many boring reasons that would make this a very long post, so I really wouldn't worry about it.

I’d be interested in those reasons.

Got burnt with a poorly-maintained M5 many years ago, swallowed my borkage life-allowance to lasting effect.

Owners seem to stay ever further away from their cars’ dirty bits, which are more unfathomable anyway - can’t find dipsticks and radiator caps now; knowledgable inspections are needed more frequently than current service intervals.

I’d love to know how continental forces use their cars differently from ours, doubt I could ever find out; some of our cars soak up incredible abuse by accounts in the “Police BMW Engine Issues” thread.

That thread also has a link on page 27 to PC Dumphries inquest. Brief summary is from 2014 police engines had 5 - 7 crank bearing failures a month. The 4th bearing in PC Dumphries car was worn and spun cutting off the oil way, which cut off supply to the 3rd bearing also, which then failed causing the con-rod to puncture the sump; some of the spilt oil caught fire and some went on the road and tyres causing the car to veer out of control. BMW UK escalated this to BMW AG who advocated more frequent oil changes and a higher grade.

Not much he could have done about it poor bloke. Don’t know the car’s history and condition.

Edited by Baddie on Saturday 1st June 11:41

[Baddie]

rottenegg said:

I feel your pain. I think we've all been victim to that. That is unfortunately why BMWs have earned a reputation for being oil leaky, unreliable, expensive money pits, and it is 100% down to poor maintenance.

German cars are engineered to a certain standard which is intolerant of shoddy workmanship and or neglect. As with any fine tolerance machine, it needs looking after.

Yes, I’ve been told, and don’t know how true it is, Japanese cars are engineered to be more tolerant of abuse / neglect / poor maintenance, and tend to perform at a lower level but with a bigger margin of reliability.

rottenegg said:

I'm not sure tbh. Maybe they left start/stop enabled or just switched them off when attending incidents? Clearly the UK police disabled it because of the reported way they use theirs, i.e. leave it idling for ages whilst dealing with an incident, and then nailing it off to another call out?

Yes, long idling time, either in-car or at incidents is a feature. They have something called ‘run-stop’ or similar, where the car can be left locked with the engine running at an incident. The thread discusses single figure MPG over a shift in things like Volvo T5’s, ST220’s, Vauxhalls and emptying a tank in a little over 100 miles, which shows how hard they’re used. Idling followed by hard dashes over 100 mph.

rottenegg said:

It's worth noting that particular issue doesn't effect civilian cars. The only public ones that were affected were caused by the EGR cooler rupturing, which BMW launched a recall campaign for, and it wasn't many in the grand scheme of things. All N57s will have, or SHOULD have had the recall done by now.

I’ve been told civilian cars are affected by the bearing issue too. Wouldn’t be surprised if this was a servicing / use issue, revved from cold, long intervals etc. I don’t know how many drivers appreciate the need to have oil up to temp on an engine with close tolerances.

rottenegg said:

Yeah that was a really nasty incident, very sad. Yeah, that is exactly what happens when main bearings spin unfortunately. Worth noting it happened on the N55 petrol turbo engine as well, not just the N57. That is why most aluminium blocks are scrap afterwards (not just BMW) as they warp from the heat, which throws out the main bearing clearance tolerances. If caught early enough, you can get away with new bearings and a crank. The upper bearings are sputter on the N57, which is a harder material than the crank, so unfortunately the crank always gets written off. Softer bearings wouldn't last long with the diesel cylinder pressures, so it's catch 22.

Interesting about the bearings and other improvements. I thought the iron versions of the M57 were pretty solid, aside from swirl flaps, but the don’t remember them all as trouble-free.

[Baddie]

Have now spoken to two independent BMW specialists who advised not to buy a car with the N57. One commented on the general decline in car engine quality, and described the N57 as “made of chocolate”.

[Baddie]

ucb said:

The opinion of the independent I spoke with yesterday on collecting my 530d was that they seem to have few problems and are generally pretty robust.

I thought that too. In context though Presitge talked about service intervals and revving from cold. Said they rebuild one N57 a week, not that many out of the number running around.

Edited by Baddie on Thursday 13th June 06:05

[Baddie]

Found this on Bimmerpost. Shows the care the engineers put into things like the forged crank, their pride comes through. But with such demanding performance/efficiency requirements and complex boost/fuelling/emissions controls with so many sensors everywhere, and sometimes 2 EGR systems, I now amazed it’s as reliable as it is.

Think stop-start may have a lot to do with bottom end failures.

https://f15.bimmerpost.com/forums/attachment.php?a...

[Baddie]

Agree with what you say, other than stop-start is known in general to wear the main bearing nearest the flywheel quite a lot more in some engines. So the manufacturers fit harder bearings (also to take the torque of modern diesels), which is why when the N57 bearings do go they take the crank with them.

Agree it's a superb engine, an amazing accomplishment of refinement, efficiency and performance when in good fettle. Interesting they went with more durable (and much cheaper to manufacture) solenoid, instead or piezo, injectors for the N57.