Home > Maintenance & Mods (L322) > Diesel virgin |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
Hard working a diesel engine on acceleration does not clear the DPF on passenger vehicles and infact quite the opposite it's a quick way of filling up the DPF with soot 2012 TDV8 Vogue (L322) |
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28th Aug 2022 2:02pm |
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Phoenix Member Since: 16 May 2022 Location: Gone Posts: 1631 |
Right so, if that's the case. why do manual / forced regen routines push more fuel into the engine (or exhaust, if so equipped) to get the exhaust (and by default, turbo) temperatures up high enough to burn off the stored soot?
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28th Aug 2022 4:08pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
Active regeneration introduces fuel into the exhaust after the combustion cycle and closes the EGR valve to raise the temperature of exhaust gases and thus the DPF core. This is not the same as revving the engine or hard accelerating . My car has run fine for the last year / 15000 miles and I've never had a DPF full warning and my last one 2 diesels did >120kmiles between them over 8 years with also no DPF warning lights or issues. Just steady driving with plenty of motorways and regular oil changes to dump the soot load in the oil. 2012 TDV8 Vogue (L322) |
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28th Aug 2022 4:33pm |
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Phoenix Member Since: 16 May 2022 Location: Gone Posts: 1631 |
EGR's are not closed during regen, otherwise the NOx values would be through the roof and the vehicle would not conform to EU5 or greater type approval. A regen (forced or otherwise) does not require greater Oxygen levels to increase the exhaust temperature, just post injection or dedicated exhaust diesel dosing injector. |
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28th Aug 2022 4:57pm |
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Bill Member Since: 18 Nov 2017 Location: Essex / Normandy Posts: 1231 |
The new car servicing requirement is every two years … the regen is achieved at much lower speeds. Filters are in fact so good that in certain circumstances, when the ambient air is already polluted, a diesel car will tend to extract more particles from the air than it emits. Emissions Analytics worked with........etc etc He who dies with the most toys wins... |
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28th Aug 2022 5:07pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
The EGR valve closes on active DPF regeneration according to the live data on my GAP IID ( one way of seeing it's in active regen mode) and the workshop manual. Same as on my previous diesel cars with DPF's from VAG and GM. 2012 TDV8 Vogue (L322) |
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28th Aug 2022 5:12pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
Every 2 years 2012 TDV8 Vogue (L322) |
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28th Aug 2022 5:13pm |
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Phoenix Member Since: 16 May 2022 Location: Gone Posts: 1631 |
Funny that, the data I have is from VWG vehicles, using manufacturers diagnostics - EGR's definitely operate normally during regen cycles. From what i've seen on here, IID live values are not altogether reliable.
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28th Aug 2022 5:54pm |
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kevinp Member Since: 28 Sep 2019 Location: Telford Posts: 1206 |
JayGee, you proved yourself wrong when I questioned your reply earlier in this thread. I didn't know if you were right or wrong but it didn't sound right that's why I asked.
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28th Aug 2022 6:03pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
AFAIK the workshop manual PDF is downloadable from the wiki (Exhaust section - DPF description) and it's quite a detailed description of how it operates on the 4.4 TDV8. Given the EGR gases are added to reduce combustion temperatures it would likley not aid the regen process and there is also the additional problem of circulating very hot gas into a plastic intake plenum. I guess as far a emissions are concerned the regen cycle will happen outside urban areas. 2012 TDV8 Vogue (L322) |
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28th Aug 2022 6:12pm |
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Kot Member Since: 10 Mar 2021 Location: broadland Posts: 1202 |
Giving the 2nd ~Turbo a good blow in fact helps to blow out the ash in the DPF, only the soot is burnt off during Passive or Active Regeneration. If the DPF temperature is above 250C Passive Regeneration will burn off most of any soot produced. its possible you could be happily Regenerating, burning off all your soot, but slowly accumulating ash. 2018 SE SDV8 4.4 Byron Blue |
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28th Aug 2022 6:13pm |
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Kot Member Since: 10 Mar 2021 Location: broadland Posts: 1202 |
Bill -- I can see the petrol cars are every 2Y but cant see the diesels being 2Y certainly the 3L diesels are every 1Y https://www.ownerinfo.landrover.com/docume...c/G2463088 2018 SE SDV8 4.4 Byron Blue |
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28th Aug 2022 6:17pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
I made one factual error which I checked and corrected. That doesn't mean I've 'proved myself wrong'. I agree members should only state things they know are factually correct and hence why I'm posting as there is a lot of opinions and not so may facts (IMO ). 2012 TDV8 Vogue (L322) Last edited by JayGee on 28th Aug 2022 6:53pm. Edited 1 time in total |
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28th Aug 2022 6:24pm |
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JayGee Member Since: 27 Jul 2021 Location: London Posts: 3207 |
That's the first time I've heard a claim that ash can be blown out of a DPF. One reason not to exercise the 2nd turbo is it adds to the ash load every time you use it. 2012 TDV8 Vogue (L322) |
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28th Aug 2022 6:29pm |
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