You're mixing the point, Trans; the Germans are very good at designing and engineering stuff for its intended purpose.
When outside of its specified envelope though, perhaps less dependable.
The biggest issue with N57 (and the smaller N47) is their extreme use of EGR (exhaust gas recirculation) to reduce NOX emissions. EGR is very bad for an engine for most systems because it generates a large amount of soot. This soot ends up in the oil sump and it acts like a micro-abrasive which causes heavy timing chain & guide wear. The second place it builds up is the inlet manifold and this has been known to cause hot spots which burn through the plastic inlet manifold and hence the vehicle fires that have been attributed to this engine.
The police use exacerbates this because egr can run at up to around 90% recycled exhaust gas on idle and police vehicles tend to spend huge amounts of time at idle. This means the vehicles suffer from extremely dirty oil in a very short time and hence timing chain failure. I'm pretty sure in the case mentioned that bits of the chain guide broke off and caused the catastrophic failure of the engine.
The cure would be fairly simple, a software delete or restriction of the EGR but that would increase NOX emissions so BMW would not do that. Far more frequent oil changes, every 2-3k would also solve the problem but the police won't do that either. A re-design but using clean exhaust gas from after the exhaust particulate filter would clean up the soot issue and Mercedes and many large vehicles use this technique but it involves more pipework and hence cost.
What I would say to anybody buying a BMW with the N47 engine is NEVER allow the stop/start function to operate and change the oil at least twice as frequent as recommended. From 2015 onwards, the B47/B57 replaced the N versions and it is better but can still suffer the same issues unless well cared for......
After buying a Discovery Sport last year I read a lot of articles about engine failures/engine part failures. There were problems on the LR Discovery and Range Rover Evoke which weren't prevalent on larger Range Rover and Jaguars with the same engine, oil dilution caused by diesel in the oil. Seems to me that Euro 6 emissions standards have a more active egr filter using diesel to increase the heat, on the sport and evoque models there wasn't enough room under the bonnet so part of the egr system had to be accommodated 60cm further down making it harder to reach the required temperature. On short journeys if the egr was going through a cleaning cycle and this was cut short, diesel ended up in the sump, diluting the oil. LR put new algorithms in the software to pick up failed egr purges and reduce the service interval accordingly. LR is a 30,000km oil change interval, realistically that will be reduced to 20,000 km, and 7 litres of 5/30 synthetic aint cheap. Helpfully, Mrs filly has an LR app on her phone telling her the miles till the next service, and the miles till she needs to add 'adblue' to a seperate tank. It also tells her what her driving efficiency is, mpg, braking and accelerating efficiency, she normally scores 4.5/5.0 out of 5. Unfortunately, it also tells her what a **** I am when driving.
VW have had similar problems with the 2l diesel, oil service interval reduced from 30,000 km to 20,000 km, but they now add with city driving it's worth reducing that further to between 4000km - 7000km
Apparently due to 'premature acidification of oil', .
Before anyone say's how crap Landrover is, google snapped crankshafts on Audis and timing chain failures on VW's.
We used to have a Citroen Xantia with a 2.0 ltr diesel, twin turbo, it was fast, economic and you felt it would go on forever, they probably will.
We love the Landrover, in terms of luxury, equipment, comfort/ride, the 9 speed auto gearbox (our 1st automatic), but, as with any modern ultra low emission diesel, you cant help feeling that a very expensive disaster is just around the corner.
Maybe it's time to go back to petrol engines, or it would have been if they hadn't brought in E10.
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