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-   -   DPF soot rising very quickly prompting too frequent regens? (https://www.bimmerfest.com/forums/showthread.php?t=917033)

AU Pete 06-12-2016 02:07 AM

DPF soot rising very quickly prompting too frequent regens?
 
firstly - sorry, I've posted a flurry of questions lately. I really do appreciate the help of everyone that is providing valuable advice.

------

Now - my 2007 X5 3.0d with 125,000km (have owned it for 1 year) had the dreaded 'DPF Blocked' message twice 3-4 months ago. After repeated forced regens, I had the thermostats changed thanks to advice on this forum and in particular edycol - which got my regens happening again. Somehow 2 mechanics did not think to look at the thermostats.

I recently got the Carly app and have been happily watching regens now occur on the highway. Problem is - the regens are occurring very frequently, and the soot level is climbing very quickly after each regen.

Before a regen, Carly tells me soot mass is around 42g, and ash mass is about 36g.

Immediately after a regen, the soot mass drops to 4g. But then within 3 minutes of continued highway driving the soot mass has climbed right back to 25g, and then within 30-40 minutes the soot mass is back up to around 40-42g. The last 4 or so regens (since I've had the carly app) have occurred about every 80km.

I'm not seeing any warning lights on the idrive/dash, but using Carly I can see an intermittent 'hidden' fault appearing which is

- Fault: Particle filter system
- Code: 004667

So - Why would the soot mass be rising so quickly? Could it be that its so clogged with ash that repeated regens are having little benefit? While I don't know specifically what oil I have in the engine, that was my BMW indy mechanics first thought 3 months ago when he serviced it for the first time, and we're now making sure BMW approved low ash oil is in it and being changed every 6 months from now on.

I am unaware of what oil was used prior to me owning the car, service records were in order BUT, the timing chain broke after the oil pump seized 2 months into ownership. Thats another thread yet to be written - but I'm mentioning it here as there's a suspicion it didn't have the right oil used in its earlier life, so perhaps that has shortened the life of the DPF...

I know of a place in Sydney (http://www.dpfcleaning.com.au/) that will clean the DPF for around $750 depending on what they find. Or I'm wondering if my DPF is one of the ones that are easily removable and I could attempt a DIY clean like this - http://5series.net/forums/diy-do-you...nce-dpf-94725/.

Any thoughts on either of those options - or whats going on?

I love how this car drives but the list of things to fix has aged me a few extra years :) I guess the wonders of computers is making me aware of things I would have otherwise not seen.

Thankyou, Pete

-----

PS: At the same time I'm researching a glow plug error code - likely the controller module, heres that thread, and I have had at least some oil in the turbo air intake, and likely the intercooler (thread) - I'm mentioning these in case they could have some relevance to this specific DPF issue.

Doug Huffman 06-12-2016 05:00 AM

OTR - Over The Road - tractors' DPF are intended to be removed and cleaned periodically by third party contractors. I pray that service will be available for automotive DPF at an economical fraction of the removal/replacement cost.

AU Pete 06-12-2016 02:17 PM

At this point I'm considering trying an additive that I'm expecting won't make much difference - but if it's only a few dollars, maybe worth the gamble...

http://m.supercheapauto.com.au/Produ...ae-Stop/347774

Thoughts?

Could a fuel additive like that cause more problems than it tries to fix?

ard 06-12-2016 02:20 PM

Just a question...HOW does the system calculate soot and ash mass??? Im not sure I trust those measurements as accurate. Either the low value right after regen or the second reading minutes later....

AU Pete 06-12-2016 02:24 PM

Quote:

Originally Posted by ard (Post 9714445)
Just a question...HOW does the system calculate soot and ash mass??? Im not sure I trust those measurements as accurate. Either the low value right after regen or the second reading minutes later....


I'm curious about that too. I suspect it's a guess based on the distance the DPF has done, combined with some back pressure values from some sensors. There's a looooong list of parameters available in Carly to monitor - so I'll try to decipher some of those to get some raw sensor values...

AU Pete 06-12-2016 02:27 PM

DPF soot rising very quickly prompting too frequent regens?
 
For all I know this process of repeated short regens may be completely normal for the computer to action after a long period of no regens / blockage

Doug Huffman 06-12-2016 02:38 PM

Last I looked, my average mileage between regenerations was a bit more than 150 miles.

Aufgeblassen 06-12-2016 03:32 PM

Quote:

Originally Posted by PotsyDriver (Post 9714438)

Could a fuel additive like that cause more problems than it tries to fix?

http://rlv.zcache.com/i_doubt_it_bum..._8byvr_512.jpg

ninja_zx11 06-12-2016 08:04 PM

Quote:

Originally Posted by ard (Post 9714445)
Just a question...HOW does the system calculate soot and ash mass??? Im not sure I trust those measurements as accurate. Either the low value right after regen or the second reading minutes later....

I think DDE calculates the flow resistance of the DPF by monitoring the pressure difference between readings before and after particulate filter to calculate the soot load.

edycol 06-12-2016 08:14 PM

Hmmm, for me red flag is seized oil pump. Why it seized? It could be that:
1. Wrong oil was used
2. That when oil pump seized DPF got clogged with more oil vapors then what it would be normal and that due to the amount of oil regeneration cannot burn it.
I am not sure whether I would believe those measurements on Carly.
This is my 5 cents. It could be just that wrong oil was used before you became an owner together with heavy city driving.

n1das 06-12-2016 09:45 PM

I think something is causing the engine to make a lot of soot and that needs to be found and taken care of ASAP. Could be something as simple as a boost leak and causing it to roll coal. Could be a number of other things. If the car didn't have a DPF you probably would see it as visible black smoke ("rolling coal").

Visible smoke from a diesel without a DPF previously was useful as a diagnostic tool. By paying attention to the amount of smoke, type of smoke, and the conditions when it is produced, you could get an idea of what's going on inside the engine. Now with our DPF equipped diesels, the DPF does a good job of "hiding" smoke such that it's possible to have a soot problem and not know it until the DPF is loaded up prematurely. That means it's important to stay on top of all maintenance and quickly take care of anything that would cause the engine to make a lot of soot.

I think the DPF is OK but something is causing the engine to roll coal and load the DPF up very quickly.

Good luck.

Sent from my Nexus 6 using Tapatalk

ard 06-12-2016 11:29 PM

Quote:

Originally Posted by ninja_zx11 (Post 9714854)
I think DDE calculates the flow resistance of the DPF by monitoring the pressure difference between readings before and after particulate filter to calculate the soot load.

One possibility:

It may be the computer sets the value to 0 immediately after a regen, based on the assumption it has just been cleaned/emptied...but then, rapidly, as you drive the sensors (flow resistance, pressure differentials) become apparent and the computer then recalculates the soot load.

Which would mean it isnt creating massive amounts of soot and clogging, rather it is clogged and remains clogs- OR the sensors that are used to calculate the loads are somehow in error....

Just my 2 cents...have not paid much attention to this.

AU Pete 06-13-2016 12:50 AM

Quote:

Originally Posted by edycol (Post 9714870)
Hmmm, for me red flag is seized oil pump. Why it seized? It could be that:
1. Wrong oil was used
2. That when oil pump seized DPF got clogged with more oil vapors then what it would be normal

Yep - and that unknown has caused me a lot of stress, at the time, and now in trying to minimise future problems.

Quote:

Originally Posted by n1das (Post 9714956)
I think something is causing the engine to make a lot of soot and that needs to be found and taken care of ASAP. Could be something as simple as a boost leak and causing it to roll coal. Could be a number of other things. If the car didn't have a DPF you probably would see it as visible black smoke ("rolling coal").

Thank you - makes sense (the DPF hiding smoke/warning signs).
I think I'm going to have to see my indy mechanic.

The car is using ZERO oil... literally not dropping a mm on the dipstick over the last few months and I'm checking it weekly.

My mechanic at the last service was concerned about some oil in the turbo air intake hose, and thus the longevity of the turbo. He was concerned that, given the history with the oil pump seizing, that the turbo oil supply line might be less than great, and over time it might starve of oil. But theres no sign of it failing - or using any oil at all. And it drives great. I don't really have anything to compare it to, but in sport mode in particular its *quick*. No lag, no flat spots - pulls hard all the way to redline.

Aufgeblassen 06-13-2016 05:33 AM

Quote:

Originally Posted by n1das (Post 9714956)
I think something is causing the engine to make a lot of soot and that needs to be found and taken care of ASAP.

The cause of massive soot is retarded injection timing. At the same time, your MPG and power would be greatly diminished.

If your MPG is perfectly normal, then you are not making excessive soot.

edycol 06-13-2016 08:40 AM

Quote:

Originally Posted by PotsyDriver (Post 9715061)
Yep - and that unknown has caused me a lot of stress, at the time, and now in trying to minimise future problems.



Thank you - makes sense (the DPF hiding smoke/warning signs).
I think I'm going to have to see my indy mechanic.

The car is using ZERO oil... literally not dropping a mm on the dipstick over the last few months and I'm checking it weekly.

My mechanic at the last service was concerned about some oil in the turbo air intake hose, and thus the longevity of the turbo. He was concerned that, given the history with the oil pump seizing, that the turbo oil supply line might be less than great, and over time it might starve of oil. But theres no sign of it failing - or using any oil at all. And it drives great. I don't really have anything to compare it to, but in sport mode in particular its *quick*. No lag, no flat spots - pulls hard all the way to redline.

I would also zero in on turbo oil supply line and change it. I am not sure why oil pump seized, but some VW engines seized due to wrong oil being used and that line might have some sludge left in.
Oil in turbo intake hose is I believe evaporation loss of oil you are using. Switch to something more stable like Mobil1 5W30 ESP, Shell Helix Ultra (very low evaporation loss) that meet LL-04.

AU Pete 06-19-2016 04:43 PM

I've not had a chance to get the car to the mechanic yet.

But just researching causes of excessive soot, (still 50% suspecting Carly may be reporting incorrect figures, but researching excessive soot causes anyway) on this other board they mention a blocked 'turbo breather' would be a creator of soot problems which generally doesn't cause power issues. Is this part the same as the 'crankcase breather filter'?

It's possible I have the old "sponge / loo role breather" - so changing to a newer Vortex filter may be in order...? it doesn't look like it was changed as part of recent services, and i have no history beyond a year back

Plausible cause of soot in this case and good thing to change anyway?

I figured it looked like an easy DIY so something i could do prior to seeing mechanic

edycol 06-19-2016 05:55 PM

Quote:

Originally Posted by PotsyDriver (Post 9724518)
I've not had a chance to get the car to the mechanic yet.

But just researching causes of excessive soot, (still 50% suspecting Carly may be reporting incorrect figures, but researching excessive soot causes anyway) on this other board they mention a blocked 'turbo breather' would be a creator of soot problems which generally doesn't cause power issues. Is this part the same as the 'crankcase breather filter'?

It's possible I have the old "sponge / loo role breather" - so changing to a newer Vortex filter may be in order...? it doesn't look like it was changed as part of recent services, and i have no history beyond a year back

Plausible cause of soot in this case and good thing to change anyway?

I figured it looked like an easy DIY so something i could do prior to seeing mechanic

if it is breather probably wrong oil was used.
I always stay amazed when people say: oh I use "synthetic" oil. Yeah, but what synthetic oil s more important.

AU Pete 06-19-2016 06:13 PM

Quote:

Originally Posted by edycol (Post 9724581)
if it is breather probably wrong oil was used.
I always stay amazed when people say: oh I use "synthetic" oil. Yeah, but what synthetic oil s more important.

point taken. not having that history of oil used before I got the car, I'm thinking a good plan of attack is to replace regardless.

Hypothetical general question - Do you think if the correct oil was used for the entire life of one of these diesels, the breather (old style foam loo roll type) would not block up?

edycol 06-19-2016 06:20 PM

Quote:

Originally Posted by PotsyDriver (Post 9724599)
point taken. not having that history of oil used before I got the car, I'm thinking a good plan of attack is to replace regardless.

Hypothetical general question - Do you think if the correct oil was used for the entire life of one of these diesels, the breather (old style foam loo roll type) would not block up?

Probably not. I have seen numerous 3.0ltr engines, single and twin turbos, and they rarely developed this issue if proper oil is used and if they are driven the way BMW is made to be driven.
I am again pointing to my brothers E61 525d that racked up some 290K (miles) and never had single issue except thermostat (other stuff that was replaced was part of regular maintenance).
But he always used BMW LL-04 oil and car saw speeds upward of 120mph all the time (this is in Europe).
Change breather, and considering that you know what you doing, just keep good maintenance and do not be shy to step on it.
From all your posts I think that car was bit neglected by previous owner.

AU Pete 06-22-2016 04:07 PM

Update: spoke to a guy that cleans DPFs daily. He said (and also makes sense after more research on a variety of makes) it's the classic signs of a DPF nearing the end of its useful life (distance between regens dropping to under 100km). His theory was when a manufacturer says 'lifetime' service from a DPF, they're meaning about 200,000km or 10 years. So that, coupled with not knowing what oil was in it before I owned it, or if it just putted around the city for 100,000km I'm going to get the DPF removed and cleaned. At least that will give a good baseline with ash & soot completely removed, and then if there are problems remaining I can deal with those better knowing 100% the DPF is not simply clogging up. Cost of this is $650 (AUS dollars).

The Carly app, or the car, calculating the soot gram amount is based on a variety of pressure numbers, and distance the car has travelled etc, so its probably more indicative of absolute pressure in the DPF, and not literally soot. Which is pretty much what ARD said above. (with the sensors recalculating the estimated soot level on the fly based on pressure)

So next step is to get my mechanic to remove the DPF and we send it off to the pro cleaner. (Unfortunately the cleaner isn't a mechanic so doesn't do the end to end service).

The other option is I attempt to remove the DPF myself and take off the sensors etc. But I can't see any DIY writeups on physically removing it, and clearance under the car probably makes it a no go.

Anyone know if the car will need to be remapped or anything once the cleaned DPF goes back on? or just plug it in and the computer (hopefully) sorts out the resetting of numbers via various sensors?

AU Pete 06-22-2016 04:32 PM

Oh, and I also have some pretty graphs to share. These are using parameters logged by the Carly app, then put through a spreadsheet app + photoshop to overlay the various parameters.

I wanted to see if Liqui-Moly Diesel Particulate Anti-ClogAlgae Stop fuel additive did anything. It looks like it may reduce the time a little for the initial regen to have an effect on the pressure. Regardless, I'm still thinking I'll get the DPF cleaned as above.

This first chart is before adding the fuel additive.
In both you can see the regens occurring.
You can click on the images to see a bigger version of each.


https://www.dropbox.com/s/7x8um0ts1v...mall.jpg?raw=1

This next chart is after adding the additive.


https://www.dropbox.com/s/lv4np2wwjm...mall.jpg?raw=1

Aufgeblassen 06-23-2016 03:11 PM

Quote:

Originally Posted by PotsyDriver (Post 9729035)
Oh, and I also have some pretty graphs to share. These are using parameters logged by the Carly app, then put through a spreadsheet app + photoshop to overlay the various parameters.

I wanted to see if Liqui-Moly Diesel Particulate Anti-ClogAlgae Stop fuel additive did anything. It looks like it may reduce the time a little for the initial regen to have an effect on the pressure. Regardless, I'm still thinking I'll get the DPF cleaned as above.

This first chart is before adding the fuel additive.
In both you can see the regens occurring.
You can click on the images to see a bigger version of each.


https://dl.dropboxusercontent.com/u/...rt-2-small.jpg

This next chart is after adding the additive.


https://dl.dropboxusercontent.com/u/...rt-1-small.jpg

So is the bottom line that you recommend us to ADD said additive, or AVOID using it? :eek::eek::eek:

AU Pete 06-23-2016 04:04 PM

Quote:

Originally Posted by Aufgeblassen (Post 9730583)
So is the bottom line that you recommend us to ADD said additive, or AVOID using it? :eek::eek::eek:

Well it's by no means an exhaustive test.
If I had the same car with only 50,000km on it, and I was not doing a good highway run once a month, I would probably add a can of it to a tank of fuel once a year. I don't think it's going to reverse the condition of your DPF, but it might extend the useful life of the DPF if its a city car and you started adding it early. Worth a $20 a year gamble anyway. Nice on topic question!

AU Pete 07-02-2016 10:01 PM

Update:

So, I was all prepped to have my DPF removed and cleaned. Then I was forced to wait as my mechanic has a massive backlog of other work (3 x BMWs with failed transmissions and 2 with blown turbos! eeeek) - anyway, I let the issue go and revisited the mechanic this week.

While he's happy to do whatever I request, he's reluctant to remove the DPF solely based on the info provided. The ash level reported isn't near the "full" level of the DPF (supposedly 100gm), and while the car is not throwing any errors, is not burning oil, and is not losing power, he thinks I should continue driving and see if it settles itself. Its possible that as we do a lot of short trips through the week/s, coupled with colder winter weather, that it is compensating by doing more frequent regens when it hits an open stretch of highway once every few weeks.

BUT - I have just stumbled across something interesting.

In the Carly app, I've been cycling through all sorts of pressure parameters and comparing those against "normal" values others report.

There's one parameter I found today that is reporting a very odd sounding number and that is "produced soot mass per time".
I don't know which sensor/s this parameter comes from (I've contacted Carly to ask).
The number being reported is generally 0.05 - 2mg/s when driving normally, but then I'm seeing a regular spike to exactly "655.349976" throughout a logged journey. You can see this in the below charts - pointed out in red.

Looks like a faulty sensor to me - somewhere. Spiking to a high number is one thing - but then the exact same number repeatedly? And I could see this spike happening when I was driving along at a constant speed - it wasn't when I was accelerating rapidly or anything.
Perhaps its not throwing an error because its only partially failed, and if its reporting "655.349976" intermittently, this would tell the computer "the soot level is rising rapidly" and thus feed into a calculated soot mass figure rising rapidly, and thus the cycle of too-frequent regens.

(all 3 charts below are over the same period of time - just different parameters stacked on top of each other. period was about 30 minutes of city driving.)

https://www.dropbox.com/s/j5wlsjromz...rt-3.png?raw=1


So - Any ideas? I feel like I'm closing in on a cause.

PS: (as an aside, I also changed the air filter yesterday, and the PCV Valve. Both looked in pretty good condition but I changed them regardless - just for peace of mind. this youtube video below proved very helpful even though its for an E53 and not an E70 - the process was pretty similar - easier on the E70 if anything).

https://www.youtube.com/watch?v=-LXBlUlgTjo

AU Pete 07-03-2016 01:22 AM

Further research leads me to the oxygen sensor.

This paper from 2009: "Different Approaches to Soot Estimation as Key Requirement for DPF Applications" which talks about soot and oxygen levels (makes sense) and mentions:

Quote:

There are 4 key parameters determining the regeneration efficiency ... soot mass on the filter, oxygen concentration, DPF inlet temperature and mass flow of the exhaust gas.
Of those 4, the temperature and pressure parameters I'm observing look normal.

But this "produced soot mass per time" parameter does not, and it sounds like the oxygen sensor would be used for estimating that.

There's a lot of interesting information in that PDF that I barely understand - but I'd put $20 on my problem being the oxygen sensor and it's slowly failing. Sound plausible?


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