chaps

A week ago I bought a 2017 SDV8 AB with full MD SH every 10k all its life - perfect maintenance!

Jan 25 last service 1k ago. Last week on collection, service indicator said 10250 miles, 870 primarily spirited motorway miles later (this week) and its gone to 5,200.

Is this oil dilution / DPF issue or blocked MAP?? Have to say its very frustrating to say the least as i do c30+k per year in them

Thanks in advance

Rich Previous
2008 TDV8 Vogue
2011 TDV8 AB (former LR1)
3.0VSE - 2015MY
Corris with Black, RSE, 22 turbines, privacy, deployables
2023 L460 P400 SE in silicone silver
2022 L460 P400 AB in black with ivory (fully loaded with deleted rear exec pack)

It can drop quickly the service distance. Particularly if its wanting to try and do a regen. Each time it tries to do a regen, it will drop the service distance a set amount ( lets argue 1k miles ).

So lets say your DPF is wanting to regen, and you're doing primarily shorter journeys around that time ( irrespective of what you've driving the timeframe before ) where it begins to regen, but doesn't finish. Each journey could in theory knock 1k miles off the service distance. A few journeys quickly knocks down the time to service in theory.

A thing to acknowledge with the DPF is that the system doesn't really care how you've filled the DPF. Whether its motorway miles, or lots of short journeys ... if its full, its full, and it only looks forward to thinking how can it regen to clear the DPF.

Personally, I've found that during a regen process, the most effective regen rate happens when you under light load maintaining between around 50 to 60mph. Imagine going up a long gentle hill. The notion of hitting the motorway and thrashng it with high revs i it is wrong for the L405 ... it doesn't work that way.

The regen system is able to heat the DPF most effectively where the engine is under load somehow ( i.e. it needs fuel delivered ) but there is headroom to add more fuel for regen purposes. If you're thrashing it, there is less headroom for additional fuel, so less regen.

Similarly, it seems to pause the rate of regen on coasting / downhill ... where you aren't needing fuel delivery ( cause if you added more fuel it would accelerate downhill which you dont really want) V8 or else ...

Fisha thank you

We have travelled back down from Shropshire this pm and the mileage travelled c 260 miles now equates to the reduction in the service mileage

The specialist activated a regen for me on Tuesday saying it had 18g of soot in it so maybe it’s had a massive regen which has reduced the interval?? Previous
2008 TDV8 Vogue
2011 TDV8 AB (former LR1)
3.0VSE - 2015MY
Corris with Black, RSE, 22 turbines, privacy, deployables
2023 L460 P400 SE in silicone silver
2022 L460 P400 AB in black with ivory (fully loaded with deleted rear exec pack)

On the IIDtool, the soot value seems to try and regen itself down to a value around 6 or 7. It'll then build up to around the 20 mark then want to regen. At about 23-24, it shows a yellow warning on the dash, and I dont know what a red warning value is. V8 or else ...

Some night time reading for nerds

https://www.fullfatrr.com/forum/topic60839.html 2018 SE SDV8 4.4 Byron Blue

^^^ I was trying to avoid pushing the poor chap off the cliff !! V8 or else ...

 2018 SE SDV8 4.4 Byron Blue

fisha wrote:

It can drop quickly the service distance.

Absolutely this.

I have been tracking my DPF related stats (thanks to the paranoia induced by this forum!). As part of that I have been capturing the distance since the last oil change and the distance to the next service. Add them together and you get the (then current) distance between services.

When the service indicator is reset it records 26,000 km to the next service. After one oil change the distance between services dropped to about 20,000 km, usually dropping slowly, and occasionally increasing slightly. Then, after a holiday towing a caravan about 1,000 miles, that distance plummeted to 15,000 km. In two weeks the distance since last oil change increased by 1,980 km, and the distance to next service dropped by 7,225 km. I changed the oil soon after that.

After the second oil change the distance between oil changes dropped quite quickly from 26,000 km to 16,000 km. No idea why. Hope that's helpful!