[CraigUK]

I've been reading a fair few posts lately on the internet regarding turbo failure on BMW turbo diesels, mainly the early E46 320D models. I'm sure most of us are aware that it is important to let the engine idle for a while to let the turbo spool down before killing the oil supply to it.

As you all know, most of the new cars now have ED fitted. I was wondering, and I'm sure someone on here will know the answer. How does the ED system guard against shutting down the engine whilst the turbo is still whistling away? I'm sure BMW must have taken care of this, if not the ED cars must eat turbos. Just a thought

[AlanQS]

The engine won't switch off until the revs return to tickover.

[CraigUK]

Alan, I thought that would be the case but even when engine revs have just reached tickover the turbo can still be spinning at a several thousand RPM. Hence the reason some cars are fitted with turbo timers.

[dxb335d]

Originally Posted by CraigUK

Alan, I thought that would be the case but even when engine revs have just reached tickover the turbo can still be spinning at a several thousand RPM. Hence the reason some cars are fitted with turbo timers.

Very true,

bit im sure in this day and age all BMW turbos will have some sort of oil supply even after shutdown.

[CraigUK]

Originally Posted by dxb335d

Very true,

bit im sure in this day and age all BMW turbos will have some sort of oil supply even after shutdown.

DXB, I'm sure they must have considered this when they went down the ED route on turbo cars. As far as I'm aware the turbos take their oil feed from the sump, almost all cars have mechanical oil pumps therefore for the turbo to retain its oil feed when the engine has turned off in ED mode an electric pump would be needed.

I'm not questioning whether or not BMW have considered this, they must have. It's more a case of how have they done this.

[F104]

What's ED?

Anyway GraigUK is right, you need an electric pump. There is an alternative, the pressure accumulator. Basically a closed reservoir that slowly gets filled with pressurized oil from say the turbo oil feed line, and whenever the oil pressure drops below reservoir pressure it feeds the engine. Thus on shutdown too.
Never understood why that hasn't caught on, as it also acts a bit like a the dry sump idea. And BMW has already a clutch delay valve they could use to fill it slowly and drain quickly...

[CraigUK]

ED = Efficient Dynamics

In essence it's a way of making the cars greener and more economical. Amongst other things it will turn your engine off when you stop at a junction or at traffic lights and then restart when you dip the clutch to go back into gear. I don't have an ED car but I'm sure someone that has can give a better description of what it does.

[mjh93sa]

I believe that one of the features of ED is that pretty much every pump is electric so that they can be used on demand and don't carry the overhead of a mechanical pump working to overcome a "worst case" scenario at all times.

Therefore they could continue to run if required.

BMW Group is front-runner in fuel efficiency in the premium segment
22.03.2007
Press Release
Munich. With the market launch of the new BMW 1 Series on March 24, 2007, the
BMW Group has set a distinct milestone in future-oriented automotive
efficiency. The latest BMW 118d is powered by a new four-cylinder105 kW/143 bhp
diesel engine with an average fuel consumption of 4.7l/100 km in the EU test
cycle and a CO2 level of 123 grams/km. Customers can now benefit from these
results, which were achieved within the framework of a development strategy
introduced around 5 years ago to effectively reduce the fuel consumption and
emission levels of petrol and diesel-powered vehicles.

Maximum fuel economy - best results in class.
The new four-cylinder diesel engines, which, like all BMW diesel power units,
are fitted with a particulate filter as standard, are heading an innovation
initiative based on the long-term development principle of efficient dynamics.
The BMW 118d - like the BMW 120d (130 kW/177 bhp, 4.9 litres, 129 grams) - is
now setting the standard for economy and emission levels in its class of
vehicle and performance. The same applies to the BMW 1 Series with petrol
engines (BMW 118i: 105 kW/143 bhp, 5.9 litres, 140 grams), all models in the
new BMW 5 Series and all new BMW 3 Series models in their respective
competitive segments. As early as 2008, the BMW Group will offer more than 30
models with maximum CO2 levels of 140 grams - from the MINI to the large BMW 5
Series.

Fuel consumption and CO2 emissions reduced by up to 20 percent.
Parallel to the innovative diesel engines, the new BMW models also feature
newly developed petrol engines with optimised fuel consumption and emissions.
BMW is the first car builder worldwide to feature High Precision Injection,
direct petrol injection technology for lean operation, which results in a
marked reduction in fuel consumption and emissions in everyday road traffic. It
is now being used on both four and six cylinder petrol engines and, combined
with further efficiency enhancing measures, achieves a significant reduction in
fuel consumption and emissions on a wide scale. In the case of the new BMW
118i, it was possible in this way to reduce fuel consumption by 19 percent
compared to the predecessor model. This is similarly applicable to the new BMW
5 Series. For example, the new BMW 530i boasts a 12 percent reduction in
average fuel consumption in comparison with its predecessor.
The new diesel engines feature third-generation Common Rail Injection and an
extremely lightweight all-aluminium crankcase. They are employed not only in
the new BMW 1 Series, but also in other series. For example, the new BMW 320d
Coupe is not only extremely attractive in appearance. Compared to its
predecessor, the two-seater also boasts a 14 percent reduction in fuel
consumption, even though power output has been boosted by 20 kW.
With regard to the six-cylinder diesel engines, the development principle of
efficient dynamics facilitates a similar relationship between increased output
and lower fuel consumption. For instance, the new BMW 535d uses 15 percent less
fuel, in spite of a 10 kW increase in output.

BMW EfficientDynamics: long-term strategy brings about extensive measures to
reduce fuel consumption and CO2 levels.
BMW EfficientDynamics is a strategy being followed by the BMW Group for many
years now and, consequently, is today already producing convincing solutions to
future-oriented demands in terms of fuel economy and emission behaviour. The
result: vehicles offering dynamic performance and significantly lower fuel
consumption and emission levels compared to their respective predecessor model.
The technological developments introduced around 5 years ago have now finally
gone into series production. The result is not only the availability of a
number of particularly efficient petrol and diesel engines, but also the
implementation of extensive measures to reduce the fuel consumption and
emissions of a wide range of new models. The highly effective package for
efficiency enhancement, which comprises technologies such as Auto Start Stop
Function or Brake Energy Recovery, is available as standard with immediate
effect, and will be employed successively in all model series.

Effective technologies for series production vehicles in all segments -
no restriction to niches or special edition models.
The new petrol and diesel engines, including accompanying measures to reduce
fuel consumption and emissions, are available for large-scale employment in a
large number of BMW Group vehicle segments. This will ensure that BMW models
will even more than before top the list in their respective competitive segment
not only in terms of performance, but also in achieving the best levels with
regard to fuel economy and emissions. Moreover, the principles of the BMW
EfficientDynamics development strategy also include the introduction of
innovations for a large number of series at an early stage and as standard
features, so that as many customers as possible may benefit from the measures
taken to improve efficiency.

Ideal additional features for more efficiency: Auto Start Stop Function, Brake
Energy Recovery, active aerodynamics.
BMW's advanced engine technology is complemented by numerous intelligent
measures taken from the hybrid kit for a reduction in fuel consumption and
emissions. This includes the Auto Start Stop Function, which automatically
switches off the engine when in neutral gear, as well as a shifting point
indicator. The latter informs the driver precisely when to change gear in order
to achieve optimum fuel economy. A further increase in efficiency is achieved
through demand-controlled and energy-saving employment of auxiliary units such
as coolant pump, a/c compressor, fuel pump, oil pump as well as newly developed
electric power steering, and through optimisation of aerodynamics such as
active control of cooling air valves.
A further significant feature: Brake Energy Recovery, made possible by
intelligent control of the generator for the on-board power supply. The
concentration of the generation of electricity on the deceleration and
acceleration phases is an excellent example of the efficient dynamics
principle. On the one hand electric power is produced predominantly without
using fuel, on the other hand, however, increased engine power is available to
be transferred into driving dynamics when accelerating.

Hybrid cooperation - technology in series development.
The development of a hybrid drive train, currently being jointly conducted by
the BMW Group, Daimler Chrysler and General Motors, will result in an even more
intensive interplay between primary and electric energy. This consists of an
active transmission and intelligent energy storage. Using this technology it
will be possible to achieve further significant gains in efficiency, both in
stop-and-go operation as well as during longer journeys on secondary roads and
motorways. Furthermore, a second collaboration between BMW and Daimler Chrysler
has been instigated to widen the ongoing development of hybrid kit technologies
for the premium segment.

On a long-term basis the BMW Group has committed itself to the use of hydrogen
as an automotive energy source. The small BMW Hydrogen 7 Series featuring a
hydrogen-powered engine already gives us a glimpse into the future of
sustainable mobility - including CO2 levels of 5 grams per km.

[foxy-367]

I asked the same question off topic in another thread It comes down to two things which were mentioned diesels generally run cooler so less likely to fry the turbo and the ED will only kick in if the engine is up to temperature so I would expect the same would happen if the coolant/oil temps were high preventing the turbo from frying.

Could be wrong tho!

Slightly o/t (I like doing this!) have you noticed whether or not stop start saves much fuel, I don't have a commute in traffic but when it does auto stop its for a minute or two at lights, it becomes a pain at roundabouts where the traffic is moving but slowly, I end up with the clutch in to stop the engine stopping!

[Carrera RSR]

Originally Posted by foxy-367

Slightly o/t (I like doing this!) have you noticed whether or not stop start saves much fuel, I don't have a commute in traffic but when it does auto stop its for a minute or two at lights, it becomes a pain at roundabouts where the traffic is moving but slowly, I end up with the clutch in to stop the engine stopping!

Use the button below the radio to switch off Start/Stop function in slow moving traffic. I quite like the peace and quiet you get when the engine is off when stationary for longer periods.

[doughboy]

From a loaner 116d ED I had in the winter, i noticed the Start / stop doesn't operate if the outside temp is 3degC or below.

So that rules out half of Europe for 4 months a year...

[F104]

Now i understand "ED" - my car has it but is not "E" or "D", i'm in discussion with the importer after 3 dealer visits (to me it is simply a bad battery)

ED is:
1) stop/start. very doubtful what we paid for it will ever result in fuel savings, it is there for BMW to hit CO emissions on the test cycle. And yes there are factors as per the manual which could prevent it from operating.
2) electric power steering - again expensive but does result in less power losses thru a permantly driven hydraulic pump
3) electric water pump on petrols, same thing as 2) above
4) NO electric oil pump. If a water pump fails you have plenty of time to react. If an oil pump fails you could be too late by the time you see the warning light...
5) Micro hybrid technoloy: the IBS (Bosch intelligent battery sensor - the black bit on the negative battery pole - has actually "Bosch IBS" on it). It tries to keep your battery at i believe 70% and use any brake/coast event to charge it to 100%. On acceleration it cuts out the alternator

All in all a pretty good approach to improved fuel economy.

[CraigUK]

I agree with you 100%, I'm happy to have an older non ED car as I would have concerns over some of the technology being used. I supose only time will tell whether or not my concerns are founded. Hopefully for ED buyers they won't be.