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Hi everyone. While I wait for my P250 to be delivered I was looking at E-Pace articles and came across this on the honestjohn.co.uk site.

" The engine is designed to have a close-coupled diesel particulate filter, which it does in longitudinal installations such as the Jaguar XE, XF and F-Pace. But the Disco Sport, Evoque and forthcoming E-Pace are all based on the old Landrover Freelander platform, which is for a transverse engine and fitting the Ingenium diesel transversely in these cars does not allow enough space between the engine and the bulkhead for a close coupled DPF to be fitted. Honda had this problem with the CR-V, and suspended production for a year until they had redesigned the floorpan and bulkhead to accept a close-coupled DPF. JLR's engineering solution has been for the engine to actively regenerate more frequently. But if a driver switches off mid active regen, that dumps post-injected diesel straight into the sump, contaminating the oil and raising its level. The obvious answer is a warning light not to switch off while regeneration is taking place, but, of course, people would find that inconvenient."

Something to keep in mind if you're an E-Pace diesel owner.
 
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How long does a regeneration cycle take ? Perhaps the better answer is to prevent engine shut down until the cycle is complete rather than have a warning light as surely that would activate on every regeneration cycle and be quite annoying !

And probably have a lot people taking the car back to the dealers thinking it's a fault
 

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That floorpan nonsense is just that.

The close coupled dpf does fit, but it is not used, instead an underfloor scrf is used.
The bit that needs heat is the diesel catalyst and that is closed coupled.

This sort of bull costs us resale value on our cars, and endangers british jobs

Honest John is just lazy journalism picking gossip and untruths from car forums
 
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Richie said:
Only just read this.

I can't say I understand the what a close-couplded DPF is but oil dilution cost me a £240 oil change after only 9k miles in 9 months since new.
Good point Richie, fortunately I have not had a problem with the DPF but I would've quite vexed if it cost me money 😡

Actually my daughter bought a Dacia three months ago and it has been in the garage for 2 months to replace the DPF !!!!
Not just JLR then but maybe the technology is flawed
 

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chicken george said:
That floorpan nonsense is just that.

The close coupled dpf does fit, but it is not used, instead an underfloor scrf is used.
The bit that needs heat is the diesel catalyst and that is closed coupled.

This sort of bull costs us resale value on our cars, and endangers british jobs

Honest John is just lazy journalism picking gossip and untruths from car forums
This is misleading information. HonestJohn's information was always factually correct and we know this today because JLR has confirmed it. Thanks are due to Sam on the RRS forum for obtaining the following letter, believed to have been sent to dealers before the first E-Pace cars shipped in 2018.

View attachment 766
 

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I generally change my car once a year or so and my last 4 cars have all been EU6 diesels with DPFs and the 5 cars before that were all EU5 diesels with DPFs. My mileage is borderline for a diesel at 12-13k miles pa with a fair mix of urban/interurban journeys with a few long runs each month (150-200 miles each way). Over the 8-9 years I have had these cars I am used to seeing an active regen every 7-10 days if I haven't done any long runs that would allow a passive regen to have taken place. I have only seen an orange DFF light once and have not seen any oil dilution or servicing issues.

If I notice an active regen is happening (reduced mpg, higher idle, no start-stop) then I make sure I let it finish even if that means an extra lap of the block or up to the next roundabout/junction and back. I enjoy driving and am rarely in a rush so it's no hassle. I probably I don't catch them all and sometimes I can't do the "extra lap" so a bit of diesel might make it through to the sump but not enough to worry me as I "catch" most of them.

I read some of the reports and articles (including the Honest John report and the JLR document posted here) before I ordered my E-Pace so did a bit more research. What I found was:

- Several reports online of early service requests due to oil dilution from incomplete active regen
- However, plenty of reports of people who are fine too
- Seems to particularly affect 16-17MY cars (Evoques & Discovery Sports)
- Software fixes/adjustments since then
- Reports a lot less in the last year (anecdotally via Google)
- As long as passive regens can happen sometimes and active regens are allowed to complete then no more issue than any other car
- Reports of oil dilution from active regens from lots of manufacturers

Additionally, I worked out that even if an extra oil change or two was required the additional 20-odd MPG compared to the equivalent petrol engined E-Pace would more than offset the cost of any additional services.

So far, the E-Pace is doing active regens about as often as my most recent two cars (a Fiat engined Jeep and a Peugeot engined Vauxhall) and the service indicator is ticking down quite nicely (dropped from 19800 miles to 19500 miles after driving 500 miles). Overall MPG is low 50s (both calculated by me and from the trip computer) and it really nice and torquey as I had expected.
 

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Can't say I've ever noticed a regeneration going on although obviously they must have. Never had a DPF warning light come on either. Maybe I've been lucky and the regens have been completed under motorway driving conditions when the effects on engine behaviour weren't noticeable
 
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rriggs said:
I generally change my car once a year or so and my last 4 cars have all been EU6 diesels with DPFs and the 5 cars before that were all EU5 diesels with DPFs. My mileage is borderline for a diesel at 12-13k miles pa with a fair mix of urban/interurban journeys with a few long runs each month (150-200 miles each way). Over the 8-9 years I have had these cars I am used to seeing an active regen every 7-10 days if I haven't done any long runs that would allow a passive regen to have taken place. I have only seen an orange DFF light once and have not seen any oil dilution or servicing issues.

If I notice an active regen is happening (reduced mpg, higher idle, no start-stop) then I make sure I let it finish even if that means an extra lap of the block or up to the next roundabout/junction and back. I enjoy driving and am rarely in a rush so it's no hassle. I probably I don't catch them all and sometimes I can't do the "extra lap" so a bit of diesel might make it through to the sump but not enough to worry me as I "catch" most of them.

I read some of the reports and articles (including the Honest John report and the JLR document posted here) before I ordered my E-Pace so did a bit more research. What I found was:

- Several reports online of early service requests due to oil dilution from incomplete active regen
- However, plenty of reports of people who are fine too
- Seems to particularly affect 16-17MY cars (Evoques & Discovery Sports)
- Software fixes/adjustments since then
- Reports a lot less in the last year (anecdotally via Google)
- As long as passive regens can happen sometimes and active regens are allowed to complete then no more issue than any other car
- Reports of oil dilution from active regens from lots of manufacturers

Additionally, I worked out that even if an extra oil change or two was required the additional 20-odd MPG compared to the equivalent petrol engined E-Pace would more than offset the cost of any additional services.

So far, the E-Pace is doing active regens about as often as my most recent two cars (a Fiat engined Jeep and a Peugeot engined Vauxhall) and the service indicator is ticking down quite nicely (dropped from 19800 miles to 19500 miles after driving 500 miles). Overall MPG is low 50s (both calculated by me and from the trip computer) and it really nice and torquey as I had expected.
Wow interesting stuff !

Like others commenting, I have not been aware of the regeneration actually occurring on my D180 and have never had a problem with the DPF in 14k miles

How long does the regeneration process last each time ? Does it vary with speed ?

If the problem can occur if the process is interrupted by shutting off the engine, why then can't we have the option of not shutting off the engine while a " regeneration ongoing light " is illuminated on the dashboard.

I suspect it is not that simple or logical 😀
 

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Active regen takes 10-15 mins

I suspect the manufacturers don't put a light because people would complain if their car does it too often (or what they consider to be too often)
 

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ctoneman said:
Like others commenting, I have not been aware of the regeneration actually occurring on my D180 and have never had a problem with the DPF in 14k miles

How long does the regeneration process last each time ? Does it vary with speed ?

If the problem can occur if the process is interrupted by shutting off the engine, why then can't we have the option of not shutting off the engine while a " regeneration ongoing light " is illuminated on the dashboard.

I suspect it is not that simple or logical 😀
Because it wouldn't achieve much for the majority of owners, I think is the answer. Engineering know that the main problem is oil dilution during normal driving, something that happens independently of the very short journeys and slow driving associated with DPF blocking. On an aged stress test of a 17MY D180 DS which was supposed to be run constantly to 100,000 miles over three months the test had to be stopped 9 times due to excessive oil dilution that threatened to wreck the test engine. The test could only be completed by changing the oil every 9,000 miles. This engine never stopped and yet it still experienced high dilution !

From this data and other scientific papers dealing with "oil dilution due to post injection" it's known that driving the car, not stopping it, is the real cause of the dilution. There is, it has to be admitted, a small increase in post injection (hence more dilution) when a regen is stopped half-way through due to the additional warm up period required. Say a long-distance driver's car needs a 5 minute warm up followed by a 20 minute burn (a typical scenario). That's 25 minutes of post injection in total, of which 20 minutes is the actual soot burning regeneration. If the car stops when the soot load is only 50% burnt, the car will complete the job next time, provided the journey is long enough. The resumed burn will also need 5 minutes to warm up the DPF to 580 deg C so the total time to regenerate the DPF in this case is 30 minutes instead of 25. It's an increase of 20% dilution and represents a reduction in service mileage of 17%.

The real problem that arises with repeatedly preventing a regen from completing is DPF blockage. If you read the JLR letter to dealers it talks about these two effects separately and makes this distinction: ALL cars will suffer dilution. Some fraction of cars will additionally get DPF clogging. They wrote this after the stress testing and the inferences to be drawn are clear.

Regarding the 10-15 minute claim. This is for an ideal installation with a close coupled DPF like on the XE or FPace. The 70 cm of pipe on the D8 acts like a heat sink and that's the second issue: the actual burns have to be longer, as well as being more frequent. A JLR powertrain engineer from Gaydon provided this information 2 months after the SCN first appeared.
 

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revoke said:
If you read the JLR letter to dealers it talks about these two effects separately and makes this distinction: ALL cars will suffer dilution. Some fraction of cars will additionally get DPF clogging. They wrote this after the stress testing and the inferences to be drawn are clear.

Regarding the 10-15 minute claim. This is for an ideal installation with a close coupled DPF like on the XE or FPace. The 70 cm of pipe on the D8 acts like a heat sink and that's the second issue: the actual burns have to be longer, as well as being more frequent. A JLR powertrain engineer from Gaydon provided this information 2 months after the SCN first appeared.
Just read the JLR letter again and I can't see where it says ALL cars will be affected by dilution. It quite clearly says that cars that do not complete the regen will be affected but is specific about that.

Each time a regen happens and i notice it, I would say that 15 minutes is about right. On my regular commute it does it begins after about 10 minutes driving. It is normally complete before the end of the 30 minute journey which is therefore about 15 minutes.
 

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You are correct, the letter to dealers does not explicitly say that "all" vehicles will suffer from dilution - nevertheless, they do. All cars that use diesel post-injection (except those fitted with a separate fifth injector) dilute the lubricating oil with diesel. What matters is the rate of accumulation of dilution, and its impact on the nominal service mileage and long-term health of the engine.

JLR set the service interval for the Jaguar XE (first JLR diesel with Ingenium) at 21,000 miles after testing showed that its close-coupled DPF enabled it to cover 21,000 miles between services while keeping dilution to a "safe" level. They set a trigger of 6.1% "estimated" diesel which is about 5% actual dilution. Here's a Jaguar XE DPF showing the flange (top right) which attaches directly to the turbo-charger outlet, the hottest part of the engine exhaust. Camera accessory Gas Font Machine Auto part


This close-coupled DPF design is used on XE/XF, Velar and F-Pace (D7a chassis) and, because of the proximity of the heat source to the DPF, it is only minimally affected by diesel dilution and 21,000 miles is usually reached before the 6.1% trigger point. Diesel dilution can still be high enough to reduce the service mileage, but nothing like the amount seen on the D8 SUVs. A Jaguar XE driven at low speed on short duration journeys might need a service at 19,000 miles but this sounds reasonable to the owner who has been told that "the nominal service interval is 21K miles but this may be shorter depending on driving style". That same reason tends to stick in the craw when being given to someone who has just seen their expected 21K service interval reduced by 70% to 6,000 miles. When JLR engineering wrote JLRP00100 explaining the problems of excessive or "higher than expected" diesel dilution on some models, the Jaguar XE was the benchmark vehicle used for comparison.

All Jaguar XE 2.0L Ingenium diesels accumulate some diesel in the oil, just like any car that uses post injection for active regeneration of its DPF. So what are the engineering "challenges" referred to in the letter to sales staff which said - and I paraphrase:

On the D8 (Evoque, DS, E-Pace). the engine and the DPF are 70 cm apart, and partially masked from one another by a bulkhead. This exhaust design will be heavily affected by Oil Dilution and DPF blockage and these issues are likely to be more common for (but not restricted to) low speed, short duration drive cycles. The impact of the distance between the heat source and the filter (DPF) can lead to failed attempts to regenerate and, as a result, so oil dilution occurs. The soot is burnt off by supplying post injected diesel to the DPF and then igniting it to burn off the soot. This process takes "around" 20 minutes. D8 vehicles which are used in a typical low-speed, low-duration drive cycles will suffer from oil dilution as a minimum but also in many cases will have blocked DPFs.
This is similar to the engineering notification sent to service departments in July 2017. Again, the words are all JLR's (when JLRP00100 appeared the E-Pace wasn't available):

The service message is being displayed early due to oil dilution caused by a higher than expected number of partial DPF regeneration cycles. The number of partial regeneration cycles is higher because the distance to complete a full regeneration is longer. This increases the probability of a given journey being interrupted compared to the same journey completed in, for example, an XE. Hardware and architectural differences between the D8 and D7a cars account for this. The amount of post injection required is much higher on Evoque/Discovery Sport which significantly increases the Fuel In Oil (FIO) contribution for each successful regeneration event. The increased post injection requirement and increased impact of interrupted regeneration on oil dilution, causes FIO to increase at a much faster rate on Land Rover models.
Behind these engineering publications lay the test results from the experiments that JLR had conducted on the Discovery Sport and Evoque to check how the D8 exhaust performed over the long term. A person on the Discovery Sport forum, almost certainly a JLR insider wrote: "I would refer you to the most recent LTT carried out at GDEC on a PTV 19MY L550 D180 which confirmed a maximum under optimum of just 9170 miles". Further on in the same thread this person remarked that all the D8 vehicles built "pre-PTA" will suffer "unavoidable fuel in oil dilution issues". I think PTV = Prototype Test Vehicle, LTT = Long-term Test(?) and GDEC = Gaydon Design & Engineering Centre.

What does 9,170 miles "maximum under optimum" mean? I'm not sure but I suspect that the best the test prototype could achieve (19MY DS) was 9,170 miles between each oil change. Presumably such long-term testing is conducted in conditions which are about as far away as it is possible to get from "low-speed, low-duration drive cycles" referred to above. It's therefore the best average that can be expected with maximum diesel dilution set at 6.1%. (with 10% dilution this rises to 15,300). There was another post on the DS forum which collated almost 100 owner reports of premature service due to diesel dilution. As the graphics below nicely illustrate, the average mileage in this population of D8 cars was just 8,300, which seems remarkably close to the figures obtained at Gaydon by JLR's long term test team. First, though, here's the DS DPF architecture for comparison with the XE. If you've got a five year old handy, ask them if they can work out where all the heat is being lost .....

Tire Wheel Automotive tire Vehicle Motor vehicle


100 users provided the raw data for these graphics: https://www.discosportforums.co.uk/viewtopic.php?f=17&t=5379&p=104505#p104505
Plot Slope Font Parallel City
Rectangle Slope Font Magenta Electric blue


N289 appears to be JLR's way of drawing a line under this unfortunate episode. Engineering seems to have been reduced to this: "We can't fix it so we are just going to hide it". There are some problems, though. Firstly, the oil dilution won't stop. It's going to keep rising at the same rate - it's just that post- N289 fewer owners will be aware of it. The possibility of mechanical failure highlighted by JLR will rise: we can predict 66% more engine failures due to 10% dilution. The DPF clogging won't go away either, in any case the dilution threshold was never relevant to the drivers affected by this because usually they never get that far.

What damage all of this might do to the engines in the long term is a separate discussion and that's not the point of this post. I just wanted to present some of the hard evidence pointing to diesel dilution affecting "every D8 diesel car" with an average mileage between services which is less than half what was originally advertised and which is still used as the "nominal" service interval. An increase in servicing costs on this scale is not due to "driving style".

Next time anyone says that to you at the stealership, ask them why it wouldn't have happened if you owned a Jaguar XE!
 

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My service warning came on last week at 9200 miles after 18 months from new, dealer has just reset service warning to allow a further 5000 miles, this should take me to the scheduled service date, does this mean I will be driving on diluted oil? would Jaguar take this sort of risk to their reputation?
D180 S.
 

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bobc said:
My service warning came on last week at 9200 miles after 18 months from new, dealer has just reset service warning to allow a further 5000 miles, this should take me to the scheduled service date, does this mean I will be driving on diluted oil? would Jaguar take this sort of risk to their reputation?
D180 S.
Yes. There are 3 counters governing the appearance of the "service required" alert: mileage, time and % diesel dilution. If the message appears prematurely then it is always due to excessive diesel dilution. See the guide for a fuller explanation.

Regarding the risk to reputation, when EU6 Nox limits were introduced in 2014-15, it was either this or risk prosecution for using VW-type software devices available on the Bosch EDC17 engine management unit. Many think that the diesel dilution and DPF blockage problems arose because JLR chose not to deploy diesel defeat devices with a problematic, too-long, too-cool exhaust architecture.

The oil service should be free for all 2016-2020 diesels up to 55,000 miles.

https://www.discosportforums.co.uk/viewtopic.php?f=8&t=10783&p=110569#p110569
 
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