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I came across this post on a JLR forum re: DPF issues.
Although not a X351 , the symptoms and cure was the same.
Its a great read and guaranteed you will fully understand what is going on with your DPF
https://www.fullfatrr.com/forum/topic48068.html
My issues were due to small slow journey to work ( 20 miles) and not allowing passive regens to complete, leading to Amber and Red warnings; the resolution was to purchase a bluetooth ODB reader and monitor soot levels, i can see and allow passive regens to complete successfully and have not had any DPF issues since. The application i use with the dongle is AUTEL diagnostics
The only way you can see a DPF regen is taking place is when the NO changes to a YES as in the first item in the picture, other methods are to view the exhaust gas temps as thry shoot up to 600c when regen starts s in progress. Over time, i now understand how much soot builds up on my daily slow journeys and approx mileage when a passive regen is due, normally for me it is 2 - 3 days or 60 miles, i make sure i extend my journey when a passive regen has started, doesn’t take long 5-10 minutes and speeds over 40 miles per hour.
Initially i used the tool to force a full active regen and maintained ever since.
happy to discuss with others in same situation.
PS , i got the same errors when DPF issues were occurring, but after the forced regen and allowing passive regens to complete, its all been good.
Make sure you read the full article, there is some great information in there , especially around the causes and when regens should be taking place at what soot levels.
Guarantee once you read whole article nothing DPF will be misunderstood.
Just for sharing correct info:
In fact there are some wrong statements on the threat. Passive regen do happen all the time when we are driving if the DPF temp exeeds +250C. Thats why its called passive. Active regen are launhed by ECU based on sensors and driving style. (Correct: Active regen can be forced too)
City driving are not bad for DPF, its there to collect the soot for clean city air and burned away when in highway. It´s the missing highway runs what are bad. (in fact, 20min of +60km/h / 40mil/h of normal driving are enough. No high rews are needed, the high rews may even harm the burning process, because the post combustion fuel injection, what are needed to ignite the DPF burning, may ingnite too early and needed heat may not reach the DPF)
Pure soot ash do not accumulate on DPF. It will complete burn away on high temp of burning process. Its the other particles what may enter on DPF what dosent burn away or leave ash when they burn. Exsample: sand dust, inpurities of fuel, particles of wrong engine oil etc.
Two most important thing when servicing modern Diesel engine: Change engine airfilter often and use correct Low Ash engine oil. The use of wrong engine oil is the most reason for DPF problems, assuming that everything else is wroking correctly on engine. Using something else than Low Ash engine oil can cause DPF problems because oil might have components what do not burn away on DPF or leave ash when burned. Low Ash oils are meant for DPF, so all components used on that oil will burn away.
DPF burning are not an miracle tool. Exsample one faulty injector can cause so much soot for DPF that no burning process can handle it, even running active burning all the time.
Been driven myself two 2.2l diesel engines over 450t km / +280t Mil and current 3.0D at the moment 300t km /+184t Mil, without any work done for DPF:s. Flushed the first 2.2l DPF at 200t km / 125t Mil, just for curiosity, but would not need to.
On my 300t km driven 3.0D XJ the measured smoke value was 0,02 in MOT at last May.
Apologies, but to disagree with your statement, passive regens are not happening ALL the time, they happen when the soot levels reach a certain level - in my case 20g/M3, then you can see a "passive regen" kick in, only with a tool!
If you switch off your engine during these passive regens regularly as they are invisible to you without tools and therefore you have no idea one is in process, this is when you start to see DPF issues build.
I am not technical nor an expert, this is just what I have experienced in my time with my car and shared if others experience the same.
You are mixing passive and active regens. Sure, turning vehicle off when active regen are on, cut the process and it will needed to start again. Every active DPF burning process do add more fuel to the engine oil. (active regen are made by adding post combustion fuel cycle)
I value your experiencement, but it is worth to use correct terms. You might want to read more this part of the X351 - Service and Repair Manual available from the Sticky section of this forum. (page 1644)
It continues with explanation of each component and their princibles. I recomment to read it, if you have any consern of your DPF. It have also full DTC code explanations and recommended actions.
Or if you like in Wikipedia https://en.wikipedia.org/wiki/Diesel_particulate_filter "Passive regeneration takes place normally while driving, when engine load and vehicle drive-cycle create temperatures that are high enough to regenerate the soot buildup on the DPF walls. Active regeneration happens while the vehicle is in use, when low engine load and lower exhaust gas temperatures inhibit the naturally occurring passive regeneration. Sensors upstream and downstream of the DPF (or a differential pressure sensor) provide readings that initiate a metered addition of fuel into the exhaust stream. There are two methods to inject fuel, either downstream injection directly into the exhaust stream, downstream of the turbo, or fuel injection into the engine cylinders on the exhaust stroke. This fuel and exhaust gas mixture passes through the Diesel Oxidation Catalyst (DOC) creating temperatures high enough to burn off the accumulated soot."
Giving out wrong information can be fatal to somebody who are doing actions with it.
(I am actually an degree vehicle engineer, but never worked as. In fact i have learned more vehicle tech with my past hobby. I used to build racecars and compete with them)
Cheers.
Thanks , this is what I was referring, anyway , you are the expert and I am not, I was just sharing "USER" experience and not those of "EXPERTS" such as yourself,
Keep up the great work, not sure of your audience.
Yes, thats why i like to correct it on my post. The Passive Renegation term on that article are not correct. (not a big deal, but good to know)
However: Nobody knows everything, so collective efforts and sharing knowhow are extremely good for everyone.
I am not count myself an expert, but i am very interested how everything works. (its hard to not dismantle the new very thin laptop to see how manufacturer managed RAM, SSD, WiFi etc or are they all soldered chips..? )
07-11-2023 | 05:59 PM
Jaguar Land Rover DPF issues
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