Exhaust System How to Clean DPF by Using It

Discussion in '8th Generation (2008-2015) [Acura TSX]' started by southerscale, Monday 17th Mar, 2014.

  1. southerscale Junior Member ☆ ☆ ☆ ☆ ☆

    I have been on this forum to effectively complain that my accord was getting nothing like the miles per gallon of other users. Being new to the Accord 8th Generation Dtec on a motorway I tended to keep the revs low within the precept arrows and only open it on A and B country roads. Recent Journeys tended to be small and local though it did include 3 miles of dual carriageway very often we were only getting 36 MPG.

    Now until now I did not know of how to nurture my DPF until the warning light for problems with it came straight on and I had to go to a main dealer for a reset and cleanout. Now looking at forums for this and other diesels suggest giving the engine a good constant work. The problem being I cannot tell what state the DPF is and how blocked it is, when it comes to its next regeneration.

    With my new found knowledge and clean DPF I purposely drove at higher revs at 75 mph on the motorway in 5th for 10 mins. Then went about my drive along the motorway without trying to save fuel. On the way back I decided to save fuel the trip meter was set I trundled along at 55 mph in 6th gear the car produced about 48 MPG over 50 miles travelled. I was now bored and put my foot down which gave the engine some work being at 2200 RPM + surprisingly the MPG did not go down on the same setting though this part of the journey was around 75MPH it got even better and the car had some poke which for the first time was discernable.

    Has anyone heard of the regeneration system being a method of using fuel constantly or at least to a greater extent when the engine is used at lowered revs to conserve fuel in the normal way of things. It seemed that the little blast I gave the car had cleared its throat of carbon. The best analogy I can give is the car has internal bleeding, it is bleeding but you cannot see it apart from at the pump or in the DPF.


    Plus the manual suggests driving at 37 MPH for 10mins this does mention what gear you have be in to get the revs right to make the engine work. Can I ask the question what the consensus is to give a DPF a good seeing to?
     
  2. Ichiban Founder Staff Team

    England CJ Leeds
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    My advise ring the neck of the car once a week, its as good as a apple a day keeps the doctor away. Ringing the neck will get that DPF into near melt temperatures.

    So don't look at the MPG when you ringing it , it will depress you.
     
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  3. Doc Expert Advisor ★ ★ ★ ★ ★

    Matt Peterborough
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    The engines method of regeneration is to increase the fuel being used for a set period of time, this causes the exhaust to heat up and burn the debris in the DPF. Effectively by holding the car at higher revs you've replicated this action. The best way and place to do it would be 5th gear and hold at high revs on a motorway.

    Tbh you'd probaly get better MPG by going a bit faster than 55 mph. That way the momentum of the car would work with you. I can get 50 MPG at 70 mph in an I-CTDI without trying to conserve fuel, and can manage over 60 MPG if I drive conservatively. The I-DTEC should produce better MPG figures than the I-CTDI.
     
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  4. southerscale Junior Member ☆ ☆ ☆ ☆ ☆

    Thank bothof you I am going to give the car a good run up to Scotland and back over the weekend from Manchester so I will able to see if I can get the figures quoted by others in terms MPG. Also its nice to be able to feel that I do have 150 BHP under the bonnet now rather than a elastic band, I had not come across DPF's till now but I am learning fast and due to the cost of the clean up at the main dealer very keen for it to stay clean as a whistle.
     
  5. cred Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom London
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    Interesting thread - the other day on the way back I drove back home the last leg of 10 miles at around 65 mph with cruise on the 4th gear with revs sitting at under 3k to help clear the DPF. I'm at odds whether that was enough?

    Also, before anyone asks, no the DPF cleaning angels did not descend onto my car and as a matter of fact nothing extraordinary happened. I am wondering if you actually ever get to know the system is flushing itself out?
     
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  6. Doc Expert Advisor ★ ★ ★ ★ ★

    Matt Peterborough
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    There are lights on the dash board which relate to the DPF but i'm not sure if they illuminate when the DPF regenerates or only when there's a problem. Someone else will need to confirm that. I think the normal regen process takes about 20 minutes to complete to give you a rough guide.

    If you're driving long journeys the DPF will be far cleaner anyway than one which does short journeys so you'll notice less of a difference in performance. But if you're only doing short journeys then maybe you could try doing it for longer and/or a couple of times then see if you notice any improvements.
     
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  7. Dzhedaj Junior Member ☆ ☆ ☆ ☆ ☆

    Driving at higher revs and/or speed will not clean your DPF, it may just help not get it clogged up so quickly.
    The car will only start the process of cleaning it, when a few conditions are met - the % of DPF blocked, engine temperature, etc.

    The only reliable way to see your DPF is being flushed - look at the fuel consumption. It goes higher, but it's hard to tell, since it could be an incline, wind, cargo, bad road surface, etc. But if you completely release the gas pedal and the fuel consumption doesn't drop to 0, it stays at 1-3 l/100km - the DPF is getting flushed for sure then.
     
  8. Ichiban Founder Staff Team

    England CJ Leeds
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    if you smell a dying rat from your diesel car you can be sure its regenerating , please don't be around that pollution is externally carcinogenic. Dirty diesels yuck!
     
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  9. Dzhedaj Junior Member ☆ ☆ ☆ ☆ ☆

    How would you smell anything from your exhaust by doing 50+mph? :Smile: And if you've just got home and smell this after you turned the engine off - bad news for you :Smile:
     
  10. Ichiban Founder Staff Team

    England CJ Leeds
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    stop the car and stand back with the engine running you will know or when you are carrying out a forced regenreation , even a die hard diesel fan won't be around to smell the diesel farts. http://www.iarc.fr/en/media-centre/pr/2012/pdfs/pr213_E.pdf
     
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  11. Dzhedaj Junior Member ☆ ☆ ☆ ☆ ☆

    If you suspect your car is doing the regeneration, the worst idea is to stop the car...
     
  12. Ichiban Founder Staff Team

    England CJ Leeds
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    that is correct I am not advocating it but you can experience the same on a forced static regeneration via HDS.
     
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  13. Doc Expert Advisor ★ ★ ★ ★ ★

    Matt Peterborough
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    I'm well aware of the conditions which need to be met to make the DPF regenerate.

    The regeneration works by increasing the fuel flow this causes the exhaust to heat up and burn all the material in the DPF. Driving at high revs and working the turbo will also cause the exhaust to heat up so will burn the material in the DPF. It's a different method of causing the same thing to happen!
     
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  14. Adamk Club Member ★ ☆ ☆ ☆ ☆

    Derby
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    Had my light turned off on the 20th of December cost £108.it came back on tonight looks like il be getting rid of the car as its not doin the miles
     
  15. cred Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom London
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    That's not good. What's your driving pattern like?
     
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  16. Adamk Club Member ★ ☆ ☆ ☆ ☆

    Derby
    145
    14
    Its been used just for short drives as we had twins on the 20th december (same day the car went in for the fault) so iv been backwards and forward to the hospital got it booked in at honda for tuesday next week goin to start using it more on longer runs if it comes on again then think it will have to go or remove the DPF its only done 55k so not like the miles are high
     
  17. AccordCU2 Expert Advisor ★ ★ ★ ★ ★

    There is your problem, short stop start driving clog DPF and it will happen on any new diesel car unfortunately.
    That why I swapped my diesel for petrol.
    Removing DPF will fail MOT and possibly invalidate your insurance.
    Hope you don't have problems with it any more or maybe look into buying a petrol depending on your need/circumstances.
     
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  18. ArcticFire-Account Closed Banned Getting Started

    Scotland Graham Scotland
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    I'm still not sure just how good (or bad) this stop-start technology is. If you do a high annual mileage but most of it is rush hour or local stuff then a diesel would be the best choice, but only if you lease it and renew every three years. This way you get the benefits of diesel fuel economy with the advantage of not having big garage bills as you will hopefully be able to change the car before there's any big problems.

    Or LPG of course! I still don't know why it's still so rare? Surely LPG is the best of both worlds, so why aren't manufacturers jumping on it?

    I'm still strongly in the camp of smaller petrol engines with a turbo being the way forward until oil is replaced with another technology.
     
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  19. Adamk Club Member ★ ☆ ☆ ☆ ☆

    Derby
    145
    14
    I used to do alot more driving but don't now thats why the car gets left on the drive.id like to see what the smoke readings are with out the DPF fitted.im an MOT tester but not aloud to do my own car but if it passes with out it im sure the guys who test it will let it go
     
  20. Adamk Club Member ★ ☆ ☆ ☆ ☆

    Derby
    145
    14
    As for getting rid of it im goin to have a shop round at the weekend see whats round i think