[Dashnine]

Having had an unpleasant period of time owning an S type Jag with some "issues" I do wonder if DPF regens are impacting on the service length as my old Jag used to spew out that much diesel when trying to trigger regens that some of it used to end up in the sump diluting what oil was in there.. Logically my mind told me there was no connection between the exhaust system and the sump that didn't involve a trip back up the exhaust and past piston rings that were compressing a volatile gas and trying to force it out of that same exhaust system but with the evidence in front of me I struggled to comprehend an alternative cause! Maybe this is why the DS service interval is the previously stated "Fairy Dust" ?

Sadly, you are correct as fuel is injected, not to be burnt in the combustion cycle, but to pass through to the exhaust. Some fuel doesn't make it and slips through and down into the sump. From ToPix:

Active regeneration of the DPF is commenced when the temperature of the DPF is increased to the combustion temperature of
the particles. The DPF temperature is raised by increasing the exhaust gas temperature. This is achieved by introducing
post-injection of fuel after the pilot and main fuel injections have occurred.

Engine oil dilution can occur due to small amounts of fuel entering the engine crankcase during the post-injection phases. This
has made it necessary to introduce a calculation based on driving style to reduce oil service intervals if necessary. The driver
is alerted to the oil service by a message in the instrument cluster.

The DPF software monitors the driving style and the frequency of the active regeneration and duration. Using this information
a calculation can be made on the engine oil dilution. When the DPF software calculates the engine oil dilution has reached a
predetermined threshold (fuel being 7% of engine oil volume) a service message is displayed in the IC.

Depending on driving style, some vehicles may require an oil service before the designated interval. If a service message is
displayed, the vehicle will be required have a full service and the service interval counter will be reset.

 

[dino16]

That's got to be the best and most lucid explanation I have seen on this subject so far. Thanks Dashnine!

 

[Dashnine]

That's got to be the best and most lucid explanation I have seen on this subject so far. Thanks Dashnine!

Sadly I can't claim it as mine - I copied the various paragraphs out of the Exhaust System DPF Operation document in the ToPix document thread. There's some good stuff in there on all aspects of the car, and in many cases giving a better explanation of how things work than you'll get from a dealer!

 

[geonic]

Thanks Dashnine! This is the first conclusive explanation for me why my DS wants a service at 1.5 years and 10k miles.

With my driving pattern with lots of short trips I assume that it has had numerous interrupted DPF regenerations and therefore a much higher number of regen cycles. Which increases the chance of oil dilution ...

 

[Mamil]

Thanks Dashnine! This is the first conclusive explanation for me why my DS wants a service at 1.5 years and 10k miles.

With my driving pattern with lots of short trips I assume that it has had numerous interrupted DPF regenerations and therefore a much higher number of regen cycles. Which increases the chance of oil dilution ...

Actually, in the same document Dashnine quoted from there's an explanation of why lots of short trips mean more dilution, and it's not about them being interrupted. It's because there are two types of DPF regeneration, active and passive.

Active is the one we all know about when the management system detects the DPF getting full and injects more fuel to raise the temperature and burn off the soot, and some of this fuel gets into the oil and dilutes it.

But when you use your car for longer & faster trips, the exhaust will naturally reach the high temperature needed to burn off the soot without the need to inject extra fuel (and the resultant oil dilution), and this is called a passive DPF regeneration. The more soot burnt off via passive regenerations, the fewer active regenerations will be needed, and the less oil dilution for the same number of miles covered.

So they key thing here is the ratio between active and passive regenerations, and if you do a lot of short journeys you have a higher proportion of active regenerations, and they are the bad ones for oil dilution.

 

[PedroT]

So a reasonable answer would be to take car on a fast run( speed limit problems) or put in S mode and use paddles to run at speed limit but take up to 2500 RPM. Do several miles like this maybe weekly will likely be useful.

 

[Mamil]

Or get a petrol engine if you do mainly short journeys

But more seriously, trying to drive the car so that passive regeneration temperatures are reached isn't very practical, so you're probably better off just letting the car do its thing with active regenerations, and changing the oil more often to compensate. Those who've seen my posts on other threads will know I'm not a fan of the extended oil change intervals LR are introducing anyway, and I do interim oil changes on my car as a matter of course. Not only does the DPF dilute the oil with fuel, but the EGR system fills it full of soot. Then with the start/stop system if you stop at lights the engine sits there hot without any oil circulation, then you accelerate off when the lights change before the oil has got up to pressure again. Unfortunately, these features are added to modern diesels to meet the emissions regulations but are not good for the long life of the engine, so IMHO regular oil changes are even more important. Meanwhile LR is going the other way pushing out the oil change intervals, mainly I think, to make the car seem more attractive at purchase time.

 

[PedroT]

Just for interest does anyone know:- How long does an Active regeneration take? And how long for Passive?

 

[Chippy]

No idea but maybe good old google can provide some information.

 

[Barnsh]

Not seen a passive time but active ranges from 10 mins to 20 mins.

 

[Dashnine]

Bit more from the manual:

Passive regeneration requires no special engine management intervention and occurs during normal engine operation. The passive regeneration involves a slow conversion of the particulate matter deposited in the DPF into carbon dioxide. This process occurs when the DPF temperature exceeds 250°C (482°F) and is a continuous process when the vehicle is being driven at higher engine loads and speeds.

During passive regeneration, only a portion of the particulate matter is converted into carbon dioxide. This is because the
chemical reaction, which utilises nitrogen dioxide, is slower than the rate of engine production of particulate matter and is
effective from 250°C (482°F).

 

[MHIGGITT]

My DS HSE Auto is 11 months old with 11k mileage and I've just had the service warning come up on both car screen and control app. I hope to contact dealer tomorrow if they're open Good Friday. Any advise what to ask for, is this a software problem or should I insist on oil change under warranty. Any help gratefully received.

MSH

 

[Dashnine]

My DS HSE Auto is 11 months old with 11k mileage and I've just had the service warning come up on both car screen and control app. I hope to contact dealer tomorrow if they're open Good Friday. Any advise what to ask for, is this a software problem or should I insist on oil change under warranty. Any help gratefully received.

MSH

Tell them the cars asking for a service and see what they say. If they say it's an error, use the info on this thread to show it's not as the car has calculated the oil is contaminated with fuel. Service should be free if you have Service plan, chargeable otherwise. It's not a warranty issue as it's not a fault but normal, expected behaviour due to the operation of the car.

 

[Hillwalker]

My dealer isn't in the know, I have been having the 'Service Required' warning for several months and several thousand miles. The dealer insists its a software problem and I have to ignore it until the 21,000 miles service. (Which is booked in a few weeks time). The warning has been on my iPhone app since about 10,000 miles, I was told to ignore that too.

Not sure what use an app is if the advice is to just ignore it.

Telling the dealer about threads on this forum is pointless, it carries no official acknowledgement, I tried and they just shrug. It was a different matter when I raised the issue of tailgate water and showed them the official LR printout I had downloaded. What we need is something similar about oil changes/consumption. They would have to take that seriously.

 

[Past master]

To be fair, that's sort of what my dealer said - they did the update and oil change, but the car wasn't due for a service for some time, and they did say it was OK to drive the car and ignore the warning until they could fit it in.

 

[Algi67]

'Not sure what use an app is if the advice is to just ignore it'

I had the service icon on the app only. This was triggered (apparently) by the oil degrading. My car had an oil / filter change and a software mod.

I personally wouldn't ignore this and push the issue with the stealer... like you say what's the point in developing this technology is LR ignore it ?

 

[Past master]

The advice was on the basis that this was a software problem and not a serious problem.
As I understand it, the warning is NOT triggered by oil degradation: it's triggered by software which ESTIMATES the oil degradation depending on your driving. So if it's really a software problem the oil may actually be fine. I think we just have to believe the dealer here, unless you want to pay someone to test the state of your oil.
However the software is now supposed to be OK, so if it happens again I shan't ignore it!

 

[Mamil]

My dealer isn't in the know, I have been having the 'Service Required' warning for several months and several thousand miles. The dealer insists its a software problem and I have to ignore it until the 21,000 miles service. (Which is booked in a few weeks time). The warning has been on my iPhone app since about 10,000 miles, I was told to ignore that too.

Not sure what use an app is if the advice is to just ignore it.

Telling the dealer about threads on this forum is pointless, it carries no official acknowledgement, I tried and they just shrug. It was a different matter when I raised the issue of tailgate water and showed them the official LR printout I had downloaded. What we need is something similar about oil changes/consumption. They would have to take that seriously.

But there is something official which says an oil change has to be done if the service message is displayed...

Diesel Particulate Filter Side Effects
The following section details some side effects caused by the active regeneration process.
Engine Oil Dilution
Engine oil dilution can occur due to small amounts of fuel entering the engine crankcase during the post-injection phases. This
has made it necessary to introduce a calculation based on driving style to reduce oil service intervals if necessary. The driver
is alerted to the oil service by a message in the instrument cluster.
The DPF software monitors the driving style and the frequency of the active regeneration and duration. Using this information
a calculation can be made on the engine oil dilution. When the DPF software calculates the engine oil dilution has reached a
predetermined threshold (fuel being 7% of engine oil volume) a service message is displayed in the IC.
Depending on driving style, some vehicles may require an oil service before the designated interval. If a service message is
displayed, the vehicle will be required have a full service and the service interval counter will be reset.

This comes straight from the Discovery Sport workshop manual - View attachment 5299 Print that off and show it to them and I don't think they can ignore that as being just forum gossip!

 

[Hillwalker]

Thanks for that, I am sure not many people are aware of this official documentation, so get fobbed off by the dealer.

It now worries me that my car should have had an oil change nearly 10,000 miles ago!

 

[Past master]

As said above, I wouldn't worry too much. It MAY be an oil problem, but you are more likely just to have the software glitch. If you are really worried it is possible to have the oil independently tested for dilution, and if the dilution is really bad you would have a case against your Land Rover dealer for not informing you of the problem or the need for the service.
LR are not recalling cars specifically to sort out the software, which IMPLIES (perhaps I'm just an optimist) that they don't believe there's a problem with the oil.