Author Topic: DPF burn initiation  (Read 1466 times)

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  • au Australia
    Melb
DPF burn initiation
« March 21, 2018, 23:03:33 »
If I wanted to intiate a DPF burn what are the conditions I need to give the engine?

How does the engine sense it needs a DPF burn? backpressure? downstream temperature/ pressure?

I've asked a service manager his technical reply was "it' ll  do it when it wants to"

How can I see a burn has taken place without watching my instantaneous fuel consumption or exhaust constantly while i'm hurtling down the road?

I've read service depts can do it via the ECU  in some cars.

Hyundai customer service were a huge disappointment

No wonder  people are scared to buy diesels if the manufacturer cant give straightforward answers and problems with the DPF can be very expensive.


  • PD CRDI

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  • au Australia
    Perth WA
Re: DPF burn initiation
« Reply #1 : March 22, 2018, 02:35:57 »
Watching this thread with interest. I was told at the 1000 km service that they initiate one at every service. I don't trust those people...
  • 2017 i30 Elite PD

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  • gb United Kingdom
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Re: DPF burn initiation
« Reply #2 : March 22, 2018, 11:32:22 »
Ours uses back pressure measured by a differential pressure sensor (our sensor happens to be faulty, hence why I know this :) )

Decent scan tools can run a manual/emergency regeneration, but these should only be used when the built in regen the car should be doing by itself has not been completing successfully.

Sent from my ONEPLUS A3003 using Tapatalk


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  • se Sweden
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Re: DPF burn initiation
« Reply #3 : March 22, 2018, 15:17:15 »
Without external guages the only way to know its taking place is the instant fuel usage meter. Or the smell that some seem to get.

It does it when the engine is warm and the exhaust flow is limited, when it does, it aims to get to 600c exhaust temp. Driving steady gets the job best done, 1500rpm or 3000 makes no difference. I have never seen the regen go active under 80kph.

Usually it starts 5km from home/work, and it wants to run 20km.

If its ended prematurley it will start/finish the regen next time the sensor tells it to, if it was let run through but there is still soot left, it will start a new burn exactly 500km from the start of the last one.
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  • dk Denmark
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Re: DPF burn initiation
« Reply #4 : March 22, 2018, 15:57:59 »
 :whsaid:

Had issue with those sensors few years ago. The light in the dash showed that DPF needed regen constantly, but engine was running fine. Error code said something like flow restricted.

There's a pressure sensor before and after the DPF and when to much difference it's time to perform a regen.

I ended up getting both sensors replaced and have had no issues since even though my daily commute is only 2x25km A roads, and only occasionally short motorway runs.
  • i40 CRDi 100 kW 2013

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Re: DPF burn initiation
« Reply #5 : March 27, 2018, 02:05:13 »
(Modified as i mixed 2 posts)

Best thing to do is drive it until its warm, observe the econometer & when it falls to something like 10L/100 Km (below half MPG it normally does), either do a motorwayrun with 2500-3000 RPM (best, as the drag from the speed increases exhaust-temperatur) or ex. 3. speed & then again, somewhere between those 25-3000 RPM to help temperature & flow to rise...The RPM is most important. It will, as stated by xiziz, last approx 20 Km for a normal regen.


:whsaid:

Had issue with those sensors few years ago. The light in the dash showed that DPF needed regen constantly, but engine was running fine. Error code said something like flow restricted.

There's a pressure sensor before and after the DPF and when to much difference it's time to perform a regen.

I ended up getting both sensors replaced and have had no issues since even though my daily commute is only 2x25km A roads, and only occasionally short motorway runs.
  • 2016 GD, 5 door hatch 1.6 CRDI 110 BHP, manual, silvergrey

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Re: DPF burn initiation
« Reply #6 : March 27, 2018, 02:15:18 »
@ChipMIK I used to think high rpm was the most important, but since I started using torque to monitor (among other things) exhaust temp, I have noticed it makes no difference. The regen cycle modulates the fuel input to achieve and hold 600c, holding engine load steady (same rpm on flat ground) will net higher time at 600c than varying the rpm(acc/decc). Hills are very bad for regen, regularly drop downwards 500c both climbing and decending.

It goes to 600c both in 1350rpm (70kph/6th) and at 3000rpm. So I have stopped doing the high rev regens.

(normal temps are 200-300c unless in a long steep hill etc)
  • i30 GD Tourer 1.6l CRDI 81kW M6 MY2014. Odo: 120k km as of Nov 2018.

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Re: DPF burn initiation
« Reply #7 : March 27, 2018, 04:22:27 »
I had full acces to all features in the ECU of my former Alfa 159 diesel, meaning i could do forced regens on it. I dont believe the engineers would set RPM for this to 3000 if 1500 was better. Remember air resistance  increases 4-fold when you double the speed.

You should try to monitor the differential pressure (DP) on the DPF when its regenerating. Youll see a higher DP then, meaning the cleaning-process is better = reason for its quicker done with higher revs than what you suggest.

Hills = Agree on downhill, uphill it helps rising the temp. As does driving with ex. caravan to keep torque up. (My caravan on hook, 5. Gear & 90 Kmt = EGT around 450-500 C)

In theory, the best regen i could think about would be Autobahn in 6. @ 3000 RPM...Uphill

I drive my car in 3. @ those 3K RPM every time i notice it regens. it does nomally around 450-500 Km betweeen "deep regens", as i believe it also does soft ones no & then to get rid of the worst soot. This i have experienced after a software-update (Believe its the Hyundai-avoidanse to WV-scandal). My i30 now does 2 Km/l shorter than before, measured brim-brim :-( & have noticed that my EGT during regens never reaches 660-670C at end of regens as it would do pre-update.

@ChipMIK I used to think high rpm was the most important, but since I started using torque to monitor (among other things) exhaust temp, I have noticed it makes no difference. The regen cycle modulates the fuel input to achieve and hold 600c, holding engine load steady (same rpm on flat ground) will net higher time at 600c than varying the rpm(acc/decc). Hills are very bad for regen, regularly drop downwards 500c both climbing and decending.

It goes to 600c both in 1350rpm (70kph/6th) and at 3000rpm. So I have stopped doing the high rev regens.

(normal temps are 200-300c unless in a long steep hill etc)
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Re: DPF burn initiation
« Reply #8 : March 27, 2018, 06:39:07 »
Interesting, I cant get it to read DP. It always seems to run 20km, no matter if I run 1500rpm or 3000rpm, sometimes I get 1000-2400km between regens, but usually 500km, app sends an alarm when over 550c egt so don't think I missed any since December when I started looking in depth.

Are forced regens done while standing still, without gears engaged the load must be low no? Maybe 3k is needed when standing still, or the pressure helps blow soot out(thought it was supposed to burn).

How do you know if its doing a soft regen? I don't think they ever did a ecu update on mine. Not that they told me about or put on an invoice.

It is still a black box in my eyes, every thing about the dpf seems hush hush and don't tell.
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Re: DPF burn initiation
« Reply #9 : March 27, 2018, 07:23:34 »
In the manual for my i40 it mention to do 1500-2000 rpm in a higher gear than second for xx miles (I don't remember) when a regen is ongoing.

Regarding my old i30 I think it said higher than 2000 revs...  In the i30 I could feel vibrations when it started regen.
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Re: DPF burn initiation
« Reply #10 : March 27, 2018, 09:10:44 »
Might be that your drivingstyle makes EGT high enough to avoid regens for that prolonged time. 95% of the time mines at 81 Kmt (GPS speed)

"Softregens": I often notice EGT rise to some 400+ C, then drops down again to 2-300 after a little while, thinking its removing some particles while doing so. Havent noticed this before the update.

While doing a forced regen, the engine must never be stopped (Needs to be at standstill), as the extra heat could damage the DPF if flow is removed whil ongoing.

DPF isnt really that hush, i just dont see anything really special about it...Except it will eventually be removed on mine when i find real confidence in my car as theres been som steering-angle issue & replaced lambda-sensor. Its still got 3 years warranty left, so bit of gamle but my idea is with shut EGR & DPF removed, brim-brim economy should be able to rise to somewhere between 26-28 kml from approx 24, perhaps even higher as the regens takes 5-8% of the fuel & EGR removed should give another 1-2 Kml at minimum at those 81 Kmt 94 km stretches i do. (Its 81 as the cruisecontrol makes me seasick between 81,1 & up to 88. Importer knows about this issue and informed me its a common issue, but doesnt care...I rest assured it will be gone when EGR has been blanked as its seems Hyundais engineers really truly sucks on this issue as any process-engineer would be able to remove it, had they access to the software :-( )
 

Interesting, I cant get it to read DP. It always seems to run 20km, no matter if I run 1500rpm or 3000rpm, sometimes I get 1000-2400km between regens, but usually 500km, app sends an alarm when over 550c egt so don't think I missed any since December when I started looking in depth.

Are forced regens done while standing still, without gears engaged the load must be low no? Maybe 3k is needed when standing still, or the pressure helps blow soot out(thought it was supposed to burn).

How do you know if its doing a soft regen? I don't think they ever did a ecu update on mine. Not that they told me about or put on an invoice.

It is still a black box in my eyes, every thing about the dpf seems hush hush and don't tell.
  • 2016 GD, 5 door hatch 1.6 CRDI 110 BHP, manual, silvergrey

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  • hr Croatia
Re: DPF burn initiation
« Reply #11 : March 28, 2018, 02:34:54 »
My i30 FD, if previous regen was done till end, does the next one 410km after the end of the previous one.
I have seen it at 400, 410, 405 even 415 km

I track this for a long time. But at first I tracked distance from start to start and ir was around 427km.

Regens last 18 minutes regardless of driving style. Regardless of driving style, exhaust temperature during the cycle goes from cca 580-650 C.

Never heard about any software update regarding this issue.

Anyone knows what system Hyundai uses for doing regens? Extra fuel line to dpf? Or more injected fuel at the end of the inject cycle?
If last one, I would expect oil rise level due to fuel dilution. (Like mazdas have). Never managed to observe it.
  • i30 1.6 CRDi 66kW with DPF, made 2011. in Czech

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  • se Sweden
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Re: DPF burn initiation
« Reply #12 : March 28, 2018, 06:02:49 »
@ChipMIK Mines with CC at 70/80kph indicated (65/75 on gps), otherwise I have to overtake everyone and there mother which ruins economy, for 95% of the time, got 75km one way to work, 67kph average speed. Mine hits over 400 in serious uphills (100+ m accent).

I switched to winter tires when I blanked my EGR so can't tell if economy is better or worse - old winter tires did 4.61l/100km, new 4.66l/km but are a lot grippier. New summer tires coming on (hopefully this weekend) so hard to make a judgement there too.

Unfortunately the CC oscillation issue did not go away or even diminish with EGR blanking, mine does the same at the same speed.

If regen occurs every 500km, and uses 10% more fuel for the 20km duration, the net increase in fuel consumption for the entire 500km distance is 0.4%. The fuel saving comes from increasing exhaust flow with a DFP-delete? Rumors are around that MOT is getting a euro regulation to check particles and nox too.

@XinZhao I think its injected at end of cycle - I have not spotted any fuel lines to dpf when I've been under the car.
  • i30 GD Tourer 1.6l CRDI 81kW M6 MY2014. Odo: 120k km as of Nov 2018.

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Re: DPF burn initiation
« Reply #13 : March 28, 2018, 08:05:13 »
Guess we just drive a bit faster in Denmark than you do up/over there in Sweden :-) I live in a bit remote area in Jutland & drive from home 0530, so not much traffic around for the first 60 or so Km...Average speed between filling up is normally around 73-74 Kmh. We dont have serious uphills here, so thats not it & EGT can differ 200C on same stretch.

I dont know age/model of your i30, but my Euro-6 16 (build march 15), goes to around 12 Kml when doing regens, which is 50% down for those 20 Km it lasts. Sometimes 250 Km between, max i have seen is 499 Km since last regen when regen just has finished, this morning it was @ 479 Km..Typically its 3 regens pr approx 50 Ltr.

Did you get engine tuned to those approx 160 BHP it can get to, as well when blanking EGR?

I have heard nothing about new regulations in DK about particles. Nox is more the catalyst part, which i will leave in the "can" where the filter is. 



@ChipMIK Mines with CC at 70/80kph indicated (65/75 on gps), otherwise I have to overtake everyone and there mother which ruins economy, for 95% of the time, got 75km one way to work, 67kph average speed. Mine hits over 400 in serious uphills (100+ m accent).

I switched to winter tires when I blanked my EGR so can't tell if economy is better or worse - old winter tires did 4.61l/100km, new 4.66l/km but are a lot grippier. New summer tires coming on (hopefully this weekend) so hard to make a judgement there too.

Unfortunately the CC oscillation issue did not go away or even diminish with EGR blanking, mine does the same at the same speed.

If regen occurs every 500km, and uses 10% more fuel for the 20km duration, the net increase in fuel consumption for the entire 500km distance is 0.4%. The fuel saving comes from increasing exhaust flow with a DFP-delete? Rumors are around that MOT is getting a euro regulation to check particles and nox too.

@XinZhao I think its injected at end of cycle - I have not spotted any fuel lines to dpf when I've been under the car.
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Re: DPF burn initiation
« Reply #14 : March 28, 2018, 08:08:50 »
You are comparing 2 differt generations of cars, with 1 model in between. No sw-update is due to yours is a FD, mine is a GD with Euro-6..Same basics, but refined & more sensors on it so irrelevant to compare, sorry :-)

DPF regens is made by injecting fuel in the exhaust-phase by normal injectors.

 

My i30 FD, if previous regen was done till end, does the next one 410km after the end of the previous one.
I have seen it at 400, 410, 405 even 415 km

I track this for a long time. But at first I tracked distance from start to start and ir was around 427km.

Regens last 18 minutes regardless of driving style. Regardless of driving style, exhaust temperature during the cycle goes from cca 580-650 C.

Never heard about any software update regarding this issue.

Anyone knows what system Hyundai uses for doing regens? Extra fuel line to dpf? Or more injected fuel at the end of the inject cycle?
If last one, I would expect oil rise level due to fuel dilution. (Like mazdas have). Never managed to observe it.
  • 2016 GD, 5 door hatch 1.6 CRDI 110 BHP, manual, silvergrey

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Re: DPF burn initiation
« Reply #15 : March 28, 2018, 08:38:17 »
On the early FD with the U engine the DPF was under the car and had fuel lines to inject directly into DPF, but on the U2 engine the DPF was moved closer to the engine, more or less build together with the exhaust manifold. On the U2 the fuel was injected from engine to DPF.
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Re: DPF burn initiation
« Reply #16 : March 28, 2018, 13:07:50 »
@ChipMIK yeah, no change in regulations for mot here yet either, but UK are toughening up mot vs dpf May 20th. So it's only a matter of time before we get there.

:link: UK government gets tough on DPF tampering ? Updated MOT test coming 20th May 2018 | Hypermiling | Fuel saving Tips | Industry News | Forum

Mines a euro5 gd,  model year 14 built and in traffic 13. Blanking plate(no hole, no ecu block) was 5gbp on ebay and 1h in the garage, ecu remapping is several thousand SEK. I was planning to do it next spring, but we will see, expensive when I don't know what the actual economy gain is. I work daytime but start early, so no to light traffic in the morning but always light traffic home as I get off at the same time the industry does. I start and end at 100m as, but pass as high as 450m or so, so pretty hilly.

 I only get the analogue reader for instant consumption, which sucks, its good for seeing if there is fuel draw while coasting(regen) or if your over 1-2l/100 km, I will see if I can set it too mpg/km/l instead over the weekend.
Even at 50% increase on regen the net fuel use is only 2% more. (which at least adds up for us doing 40k+ km annually)
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Re: DPF burn initiation
« Reply #17 : March 28, 2018, 19:30:42 »
The link you sent just proves to me that they cant detect if the DPF is there or not. On my former alfa, the DPF could be drilled from behind, leaving no trace at all that its actually not inside anymore.

I believe my Euro-6 will go to limb-home mode if i block the EGR, but only 99% sure..It really surprices med that you dont even get ECU-failure lamp on if you had it blocked for more than 3 driving-"cycles"

You must remeber the DPF typically gives some 5-+70 mBar resistance on the exhaust during any engine-running condition, so removing this will also give you a saving + more BHP @ higher revs where the DP is at its max. 

@ChipMIK yeah, no change in regulations for mot here yet either, but UK are toughening up mot vs dpf May 20th. So it's only a matter of time before we get there.

:link: UK government gets tough on DPF tampering ? Updated MOT test coming 20th May 2018 | Hypermiling | Fuel saving Tips | Industry News | Forum

Mines a euro5 gd,  model year 14 built and in traffic 13. Blanking plate(no hole, no ecu block) was 5gbp on ebay and 1h in the garage, ecu remapping is several thousand SEK. I was planning to do it next spring, but we will see, expensive when I don't know what the actual economy gain is. I work daytime but start early, so no to light traffic in the morning but always light traffic home as I get off at the same time the industry does. I start and end at 100m as, but pass as high as 450m or so, so pretty hilly.

 I only get the analogue reader for instant consumption, which sucks, its good for seeing if there is fuel draw while coasting(regen) or if your over 1-2l/100 km, I will see if I can set it too mpg/km/l instead over the weekend.
Even at 50% increase on regen the net fuel use is only 2% more. (which at least adds up for us doing 40k+ km annually)
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Re: DPF burn initiation
« Reply #18 : March 29, 2018, 03:10:06 »
@ChipMIK hmm, maybe it's not as bad as I thought. I still feel like a villain for blanking the egr, but it made the car run so much nicer sub 2k revs. DPF probably gets to stay, unless you get a very good increase in fuel economy when you do it, then I might rethink. :P

I got a blanking plate without a hole so I could test, thought it ecu would throw a fit and I'd have to drill a hole. It's been in 15000km now, no codes and torque shows it passes its egr test. :)
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  • au Australia
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Re: DPF burn initiation
« Reply #19 : March 29, 2018, 11:25:44 »
You guys have too much time on your hands.
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Re: DPF burn initiation
« Reply #20 : March 30, 2018, 19:20:30 »
Nope mate...Were just on the top of the world compared to you  :rofl: :rofl: :rofl:

You guys have too much time on your hands.
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Re: DPF burn initiation
« Reply #21 : April 13, 2018, 21:32:31 »
Nope mate...Were just on the top of the world compared to you  :rofl: :rofl: :rofl:

You guys have too much time on your hands.

Its those long, long winters.  Too cold to go outside,  potter in the garage   :lol:
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Re: DPF burn initiation
« Reply #22 : April 14, 2018, 02:09:06 »
My garage is unheated and uninsulated with a broken window, and was snowed in behind a big ridge of snow. Not where I spend my winters willingly, basement is a lot warmer and where I keep my brewing equipment. :P

Seasonal jobs.  :P
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