This is an update on my experience of owning a XJ Diesel (Euro 6) 2017 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 diagnoses my self 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 . 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 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 an additional motorway journey each weekend - 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 plan to pay for the early oil changes while the car is still under 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 appreciate comments from other XJ Diesel (Euro 6) owners of their experience 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

 

Hi Tony,

There are frequent reports of DPF issues with these engines. To me it sounds like a flaw, but I am not an owner of this engine. In fact you may get a better response by posting to jaguarforum (singular instead of plural), as I understand there are more diesel drivers on that forum.

All the best.