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This is an account of my experience of owning a XJ Diesel (Euro 6) 2017 model year that is requiring regular early oil changes that the Dealership has diagnosed as a consequence of my driving style ie. frequency of short journeys resulting in interrupted active regens causing the engine oil to be contaminated and when the level reaches 7% triggering a" service required message"
I decided to investigate this diagnosis myself and bought an iCarsoft scanner and measured the DPF soot level/oil dilution after every journey plus I also introduced additional motorway journeys to compensate for the number of short journeys to create more of a 50/50 split to better reflect average ownership . Also I ensured that there were no interrupted regens during the urban runs by taking the car on the motorway as soon as the DPF level approached 20g/m³.

Runs - 30 Urban runs of under 10 miles ( Total 51% of actual mileage ) 6 Motorway runs of around 50 miles ( 49% of actual mileage )

Distance - 586 miles ( Actual mileage) 3822 miles ( Service indicator mileage)

1. Urban runs (under 10 miles ) raise DPF soot levels by 0.32 g/m³ per mile on average

2. Motorway runs raise DPF soot levels by 0.13g/m³ per mile on average

3. Passive Regens do not clear the DPF only slow the rate of accumulation although rarely on urban runs - only on journeys driving consistently above 40mph for at least 20 minutes

4. DPF soot levels increase until 20 g/m³ then the cars system looks for opportunities to initiate Active Regens

5. Active Regens occur on average every 120 distance miles / 800 service indicator miles ( service indicator countdown - measuring the level of oil dilution)

6. Oil dilution increases by around 0.3% after every Active Regen apparently linked to the service indicator countdown prompting a "service required" message at 7% contamination

The scanner allows the driver to schedule a 20 minute/40mph journey when the soot level is approaching 20g/m³, to minimise interrupted Active Regens and/or the DPF warning light coming on. However even after introducing additional motorway journeys - I estimate that I will still require at least one possibly two early oil changes before the annual service.

For the record I love my Jag and accept in hindsight I should have purchased a petrol version however I plan to pay for the early oil changes while the car is still under the approved used warranty and then look to changing the oil myself but based on these results (assuming they are accurate) I cannot see how it would be possible to achieve 12000 miles to an annual service without an early oil change

So I would really be grateful for comments from members of their experience and I am visiting other forums to gather information to determine whether :

1. My car has a fault on the engine management or DPF operation
or
2. It is a feature of the XJ Diesel (Euro 6) on the D2A platform which may require early oil changes

For information I have read that the XJ is on the D2A platform and is medium coupled and may suffer from oil dilution whereas other models like the XE and XF are on the D7A platform which are close coupled and are not affected

Thanks
 

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I think Tony can add to your questions.

Sent from my SM-G986B using Tapatalk
 

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Yes, Tony (@G6hbq) will concur with your findings. The problem lies with the "architecture" of Euro 6 diesel XJ where the DPF is located too far down the exhaust to get hot enough.
But stand your ground regarding the reason for your early services. This is a VERY WELL KNOWN issue at Jaguar and they should not be hiding behind the "inappropriate journeys" excuse. You should have been advised about this when you purchased the car.
 
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Trying to blame your "usage" is simply appalling, but par for the JLR course. Did they warn you about that when you bought it? I doubt it.

This is a consequence of the physical architecture of the engine/DPF - the DPF is simply too far from the exhaust ports to regen "naturally" - it has to be "forced" to do so by injecting fuel on the exhaust strokes to artificially raise the exhaust gas temperature. Enough of that fuel gets past the piston rings to end up diluting the oil in the crankcase. Uncorrected that will destroy the engine.

My Euro 6 RRS did exactly the same thing after a software update, despite being used on long runs 90% of the time. I got rid while it was in warranty, and had a huge row with the dealer when they wanted to charge me for the interim oil changes (JLR had a bulletin out at the time covering free oil changes under those exact circumstances). They will not get any further business from me, ever.

Your only "fix" is, as you say, 6000 mile oil changes, or swap to a petrol vehicle.

IMHO these cars are not fit for purpose.
 
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If you like the car I wouldn’t be bother too much about it. We know the issue and we Know Jaguar is not going to do anything about it. I always change oil to my cars every 6 month or 6000 miles. Enjoy your car.
 
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Try sticking some Archoil AR6400D-MAX or AR6900D-MAX in with the fuel.

Reduces the temperature required for regens, and gives you a cleaner fuel burn creating less soot to catch in the DPF in the first place.
 

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I have documented my experience of this issue elsewhere on the forum.
Mine was asking for service every 3000m
As stated in the thread I did 300m in one day and the service indicator dropped 1500m.
Appalling service from CRC despite buying jaguars since 2001.
Loved the car but customer service was S H I T .
 
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Trying to blame your "usage" is simply appalling, but par for the JLR course. Did they warn you about that when you bought it? I doubt it.

This is a consequence of the physical architecture of the engine/DPF - the DPF is simply too far from the exhaust ports to regen "naturally" - it has to be "forced" to do so by injecting fuel on the exhaust strokes to artificially raise the exhaust gas temperature. Enough of that fuel gets past the piston rings to end up diluting the oil in the crankcase. Uncorrected that will destroy the engine.

My Euro 6 RRS did exactly the same thing after a software update, despite being used on long runs 90% of the time. I got rid while it was in warranty, and had a huge row with the dealer when they wanted to charge me for the interim oil changes (JLR had a bulletin out at the time covering free oil changes under those exact circumstances). They will not get any further business from me, ever.

Your only "fix" is, as you say, 6000 mile oil changes, or swap to a petrol vehicle.

IMHO these cars are not fit for purpose.
It wouldn't be so bad if the active regens were all successful ... but they're not. The RRS & Euro 6 XJ both struggle to force a regen compounding the problem of negligible passive regeneration.

For the record, my 2013 XFS did an active regeneration between 1100 & 1200 miles as regular as clockwork.
 
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This thread so clearly mirrors Tony’s experience a 15 - 20 months ago. I think it was the CRC response that tipped Tony to switch and me to get rid of my disco Sport at the earliest point the PCP would allow as it too was suffering oil dilution issues although to a lesser extent.
 

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Can’t they simply use an Electric DPF heater to speed up the regeneration and burn some soot even on short trips? I am sure it will be more efficient than burning more fuel.
 

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Not many heaters that can generate the necessary 600ish degrees C needed. Other than fuel.
 
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Well they can at least use it as an auxiliary source and at-least make them like XFs. but I think it contradicts one of the DPF use principals that was taking the pollution out of cities and exhaust it outside. Otherwise a normal heat gun can reach 550’C. I guess a 3-4kW heater should be enough to continue burning soot at idle.
 

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And that would muck up the rated CO2 emissions anyway.............not gonna happen!
 
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When I bought my 2014 last year, I was in the fortunate position I could have bought newer. It came down to simplistics......a Euro5 with 6k miles, or a Euro6 with four or five times that mileage and all the inherent oil dilution that went therewith. Nae contest, plus oil will be changed every 6k or less, besta diesel used. and Archoil 6900 added regularly along with Italiano Decokeo regularly.
 

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I wonder if anyone has ever considered including a mechanical scraper device which traverses the DPF, sweeping the ash into a bin for emptying.
 

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I wonder if anyone has ever considered including a mechanical scraper device which traverses the DPF, sweeping the ash into a bin for emptying.
You mean making a hole and hoover it? I guess the situation here is that it cannot burn the soot to convert it to ash.
 

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You would think they would have some form of notification on the dash so say that a DPF is in progress and that you must not switch off the car. Even better, have a safe cancel option as well.

But as mentioned Archoil AR6400-D Max is excellent stuff and when I tested using it the soot levels would actually reduce just from passive regen on the motorway. Without it I can reach over 20 grams in a week or so easy, and I do a lot of short commutes.

icarsoft is invaluable.
 
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