DPF wash out and rebuild

[Greg Roles]

Well my DPF had pretty much clogged at 120kms, and as I am still as yet to find the right sports core, I decided to recondition what I have to buy a bit more time.

The Viezu Race file no doubt led to an early fill level, and this is the reason most decent tuners won't put more than a "stage 1" or mid level performance tune on DPF equipped cars. My own DPF has gone from 3/4 filled ( 30g carbon ) which took 4 years, to the full 40g carbon in just a year of full on race files, so the soot / ash produced is too much for the general public. I was well aware of this going in though : )

Anyway my car was wanting to regen every other drive, and I only had about 50kms of range between regens, and this was driving me nuts. I decided to pull out the core and pressure wash it out, and see what happened.

Removal was relatively straight forward, and there is a great guide here (http://www.vwwatercooled.com.au/forums/f28/dpf-removal-guide-71644.html), so I won't bother writing up that proceedure. Jazd did help me with a few points, so thanks for such a great guide!!


With the DPF out, it was time to cut it open with the aim of not damaging the core. As you can see from the pics below, it sits on a small ledge top and bottom, so I cut a little above the lower weld, so as to not damage this shelf, and also used a worn down 1mm cutting blade so as to limit my entry depth. You can see I still nicked the core in a few spots. The first pic is my prototype DPF and you can see I cut a bit too low. You can see the core is about 2mm below the case, wrapped in some sort of heat shield stuff, probably asbestos, so take care!! I used a mask just in case.

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010211_zps1ee3759b-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010212_zpsa01d291a-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010214_zpsae8d83d5-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010215_zps96d78da9-1.jpg

[Greg Roles]

The core would not pull out like that as it is a snug fit, so I had to open the case further.

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010216_zpsbee7631b-1.jpg


This allowed me to remove the core, and the very delicate heat sheld, which despite your best efforts will likely fall apart. Mine broke into a few pieces by reassembly time, but I put them back in as best I could, this helps keep the heat in during regens, and you want this core to always be as hot as possible. Also very important to mark which side is the top or inlet, as you want to reverse flush the core. There are arrows on the side showing flow, but they are quite faint.

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010218_zpsdd699909-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010219_zps6c657684-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010220_zps364706fc-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010221_zps4ffd4cce-1.jpg

[Greg Roles]

Gurney time.

Well you can go to town with the pressure washer, I had mine right against the core on full power, and no physical damage at all, the core is quite strong. It is however like china and brittle, so if you drop it, you're going to be dealing with pieces! It must remain intact to allow the right pressure difference between the fore and aft pressure sensors, so I took great care not to drop mine!!

Here is what came out after a good 15-30mins of blasting up close, holding it with my foot. I got soaked as I sat down to get the water jet perfectly aligned with the long channels in the core. The non regenerable ash is white, and this is what I found the core I smashed up was full of. As you can see from the pics above, I had just finished a regen prior to cutting it open, and there is no black soot to be seen. The black stuff is not the problem!

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010222_zpsd1265dfb-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010224_zps41bb0b76-1.jpg


An awful lot of what looked like sand came out, much more than I expected, and when you pick it up and rub it between your fingers it indeed feels like ash and rubs down to nothing. It is NOT any part of the physical Silicon Carbide core!

I washed away the removed ash, and repeated washes till I could get no more white ash out with the pressure washer.

I then spent a lot more time flushing it over and over in a bucket of water, and found the best method was to lower it in top last, and allow the entering water to "float" the channel contents out each time. This got a fair bit more out, and overall I spent a good two hours washing it out, figured I wanted it as clean as humanly possible. When I got down to very little coming out and the water staying clean, it was time to put it out in the sun, and tee up my brother for some Mig welding.

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010225_zps8ab5daf9-1.jpg

Putting it back together wasn't too tricky, but we had to wire it together to pull the can back together, as I already had a 1mm blade cut to fill, and the heatshield makes pulling that gap back down quite tricky. Still a few ales and we managed it, and home I went to bake "dinner". I figured an hour in the oven to drive off as much water as possible could only help, I didn't want the car freaking out from too much back pressure with an overly wet core. Probably not essential, just me being careful. A lot of water did indeed pour out the pipe, if I put a glass over the end it quickly showed condensation.

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010226_zpsbb794e73-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2012/12/P1010227_zps386a0f7c-1.jpg

[Greg Roles]

I had intended to flip the core over, as I see no reason why this wouldn't work, and will expand on that later, but I managed to remove so much ash I figured I'd go for the maximum Cat effect. The Platinum Cat coating is integrated in the MKV core, and denser at the inlet and lessened towards the back, so flipping it would increase emissions as far as I can figure, but would allow any remaining ash to blow back out and basically give you a fresh core to fill. I will go into that on here later today.

So far so good, and I decided to reset the ash level back down to 5 grams to be safe ( 40 grams is full ) The car is running fine after a quiet test drive yesterday to blow all the water out of the core. Early days, I have a job up at Nambour this arvo, so if I make it, well I will label this process as a success.

Wish me luck!

[h100vw]

Good effort Greg. Could be a good halfway to a new core.

Gavin

[Umai Naa!!]

Top work as always.

I wonder if this is still considered as tampering? Could there be a legitimate market for this sort of thing?

[brad]

Greg
Why couldn't you leave the DPF intact & simply reverse flush with high volumes of water?

[Greg Roles]

Brad, that's the normal process you find workshops doing on YouTube, with people just blasting a gurney up the outlet, but you really would need immense pressure to clean out the very baked in ash in my opinion, and little came out of my core till I put the gurney nozzle right up to the surface of the core outlet and blasted away. To get the same effect would require some truly huge flowrates in reverse, possible, but not with anything I have. Perhaps the local firehose underneath a shopping centre?? Remember the inlet and outlet channels are not connected, and you are effectively trying to force water up the outlet, across the channel walls, and to then flush ash out of the adjacent inlet channel!

I had intended to flip it to be honest, as it is a symmetrical design apart from the Platinum, and that would allow any remaining ash to just blow out the tail pipe in operation, but it seemed to clean so bloody well I didn't bother. The DPF core I smashed up previously had very baked in ash, and it is compacted far more than you would think, years of pressure and regens will do that.

But sure a reverse flush intact would give you some effect, just not as much in my opinion, and given the removal process, you may as well do it properly. It takes some time to remove and install, although now i have done it once it would be a lot quicker second time around.

Umai, my whole business aim is to find replacement cores, sports cores, and to give people with clogged DPF aftermarket options, both stock and higher flow. Dealing with China is somewhat "difficult" though, hence me cleaning out my own core to get more time out of it.

Gav more driving today and the car is telling me that the core is at 0.0% loaded, so as far as the ECU is concerned this IS a new core. Will I get a further 120k out of it, who knows, but I will be monitoring it intensively, at least I am back to a happy car and all for a days labour.

[Transporter]

Great work Greg. Good idea to open and clean the core. :icon_rate_10:

I saw some chemicals are commercially available for cleaning the DPF without opening it, but who knows how effective they're.

[benough]

Cracker effort! You make it look easy.

That's a service I'd pay for. Removal of the core for self cleaning and reinstall.

[Jarred]

Wow, great effort, and great job.

really good to know that this can be done!

[getjet]

Very interesting read mate. Good stuff Greg.

How long do you reckon' it will last? Does the material in the DPF have a 'working' lifespan?

[Greg Roles]

Miro those DPF regen "chemicals" are designed to help burn the black soot. The better ones are Cerium based, but soot per say isn't the problem, it's the white non regenerable oil ash. You need to physicaly remove it. The white ash slowly fills the cannister, and leaves less and less "space" for the regenerable black soot. Look how clean my core looks at 5 years just after a regen when I opened it!!

My 200km drive yesterday showed me that the core is back to behaving like it "used to". In 200k I saw hardly any soot collection, and I'd assume it is filling the walls of the core at this stage, and won't start showing a load for a while yet. From new the core used to regen about once a 1000kms, and I will monitor the regens to see just how much of that capacity I have back, but bottom line is I have extended the lifespan already, and it's driving like a champion, even feels "peppier".

Get - The physical SiC ( Silicon carbide ) core is basically like a manufactured pumice stone, it is just a physical trap, and should last indefinately. The Platinum coating to aid emission reduction and act as a Cat will however deteriorate, but any decent "cat" should last 200-300kms on normal cars at least. Remember a DPF is suposed to "fill" at around 150kms.

Now how to make my sore New Years head feel "peppier"!

[tigger73]

Now how to make my sore New Years head feel "peppier"!

How about give that a back-flush too :)

[Transporter]

Miro those DPF regen "chemicals" are designed to help burn the black soot. The better ones are Cerium based.

I didn't mean the tank additive. :)

[neil]

Great read mate.

Could be an after market business in the making there. cleaning out or designing a canister that can be
easily opened and closed by the owners and retrofitted.

[Greg Roles]

The Carformance "plan" is to offer various re-cores, and I'd V-clamp the system, stuff cutting it open all the time. The bitch is dealing with China, they spam the hell out of me all the time via the website, but when you actually WANT something.......

[Greg Roles]

I didn't mean the tank additive. :)

Sorry mate, I forget you have trade knowledge, but I question how any chemical would remove ash.....soot yeah, but ash is an end product. Look at any campfire!

[Jmac]

Good stuff, ive had a couple that have broken up in service now , so replacement cores would be the go if poss. .
Jmac

[brad]

Brad, that's the normal process you find workshops doing on YouTube, with people just blasting a gurney up the outlet, but you really would need immense pressure to clean out the very baked in ash in my opinion, and little came out of my core till I put the gurney nozzle right up to the surface of the core outlet and blasted away. .
I was thinking like a firehose attached to the outlet - huge volume of water. Probably an unrealistic idea

[Greg Roles]

Anything is going to help. I figure opening it up entirely is the best way, but I am sure a firehose reverse flush would gain you a good amount of capacity back. I am still doing a lot of trial and error testing, but do believe I can now accurately work out how much ash is remaining so you can set up the DPF post washout to regen properly. You have to set the ash level in grams to an accurate amount, so the ECU can work with the pressure difference, and not over or under regen. This is paramount, but I feel I have pretty much cracked it.

Here's the thing. My DPF was at about 40 grams of carbon ( ash levels ) and that is the end of life capacity. I'm pretty sure that I'm now back down to just 4 grams. Vag Com states a clean / new DPF should have a pressure difference of between 4-9mbar at idle, and get this, my washed out core is sitting at 8.5!!!

So in a nutshell my washed core is within NEW range!!!!!!!!!!!!!

I've still a lot of testing to do, and will report on the results, but at this stage I am of the opinion I have a good as new core, and am 99% convinced that this procedure can be used to effectively regenerate any SiC ( ie all VAG ones ) core that is still intact. My MFD range per tank has gone up as well, and the car is definately performing better. I am monitoring regens, and it would seem it will be a towards a tankful before another one happens at the very very slow rate of fill. This is how it was when I bought the car : )

I'm rather pleased with myself!

[popeclement]

an excellent post - out of interest what would be the comparative costs of a dealer supplied and an OEM replacement (if available) DPF assembly ?

[Umai Naa!!]

Around $3,000 supplied and fitted through the dealership, at a close guess.

[Greg Roles]

It was a bit over $4k for the Golf when I got it, seems VW dropped their prices to a little less ludicrous lately.

You can get a rebuilt pipe out of Europe for about $1200 or so, but the ones available on Ebay etc have become of poorer quality lately.

I'd have to say anyone with a clogged core should try a washout, and this year I hope to be able to offer new standard cores, and higher flow "sports" ones, so you can turn the damn regens off altogether, comes down to legalities and how little soot I can get it to blow. I believe I can make it meet Euro V, but the latest MK6 level Euro VI emissions, well that is highly unlikely. Still you MK6 types should have a bit of time left in your DPF's, it's the older diesels like mine that are starting to clog on mass!

[gecko2k]

Good work there Greg, some DPFs can also be pressure cleaned with an air hose and compressor, can get messy so you need to have a water bucket or old towel at the other end to catch the soot :)


Sent from my iPhone using Tapatalk

[Diesel_vert]

Part of the Euro 4 emissions requirements stipulates an in-use durability requirement of 100 000 km, so at least your DPF has lasted beyond that.

Interestingly, that requirement was increased to 160 000 km for Euro 5 vehicles, so hopefully the DPF on the newer cars will last a little longer before they need "servicing".

[Greg Roles]

Any DPF equipped car is at least Euro V mate, so I got robbed! The MKV 103kw Golf and the Polo's etc all had no DPF and only met Euro IV.

I reckon the MK6's will last longer overall, as they have separated the cat component with a pre cat and post cat, and common rail is far more DPF friendly, produces far less soot overall, far better mixtures. My next diesel will definately be common rail....and not front wheel drive!!

[benough]

Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?

[Diesel_vert]

Any DPF equipped car is at least Euro V mate, so I got robbed! The MKV 103kw Golf and the Polo's etc all had no DPF and only met Euro IV.

I reckon the MK6's will last longer overall, as they have separated the cat component with a pre cat and post cat, and common rail is far more DPF friendly, produces far less soot overall, far better mixtures. My next diesel will definately be common rail....and not front wheel drive!!

The Golf Mk5 GT TDI was a Euro 4 vehicle, as were Golf Mk5 TDI models without a DPF.

[jazd]

Good stuff Greg, great results. I would also say from my experience that it would be pretty hard to remove all the ash with even a high pressure hose without taking the core out.


Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?
Its not a code, its one of the measuring blocks. Mine was also pretty healthy at 120,000km or so and had a tune since 80,000.

[h100vw]

Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?

h Groups at once 070 and 075.
[Go!]
MVB 070.1: Regeneration Status (xxxxxxx1 = Normal Regeneration active, xxxxxx1x = Forced Regeneration active)
MVB 070.3: Regeneration Counter/Timer
MVB 075.1: Exhaust Gas Temperature before Turbo Charger
MVB 075.2: Exhaust Gas Temperature before Particle Filter
MVB 075.3: Particle Filter Load
MVB 075.4: Exhaust Gas Temperature after Particle Filter
Now Start the Driving Cycle and keep watching the Measuring Blocks (2nd Person required).

From here
Diesel Particle Filter Emergency Regeneration - Ross-Tech Wiki (http://wiki.ross-tech.com/wiki/index.php/Diesel_Particle_Filter_Emergency_Regeneration)

Cheers
Gavin

[Greg Roles]

Channel 067 and 068 give you actual ash, and are interesting too, shows you the pressure difference, and if you hover ( with the update pack I believe, ) you get the pressure thresholds it should fall within. Basically at 300mbar it's game over.

I will do a full how to writeup on the weekend, still finishing my experiments, but it;s all good : )

Gav ol mate 075 and 070 are the soot levels and regen status, that you can regen down. "Particle filter load" refers to that regenerable component. Actual oil ash that eventually blocks the thing is called "carbon level" and is the whole problem, as it isn't regenerable. It does get confusing, with the soot regenning at 40% filter load, and the DPF clogging at 40g "carbon" ( ash ) load.

I'll do a how to / explanation on the weekend : )

[Greg Roles]

The Golf Mk5 GT TDI was a Euro 4 vehicle, as were Golf Mk5 TDI models without a DPF.

Mate whole point of the DPF was to meet Euro V - perhaps revisit your tech bulletins?? : ) Anyway who cares really, if you have one, it's going to need a wash eventually....and it friggen works. YAY!!

[Greg Roles]

A definitive write up will be a little while yet, the ECU is still learning and adapting, and I am yet to be convinced I have it totally nailed. It is all looking very good thus far, and my first regen didn't happen till mid 500kms, which is how I remember it used to be. It also regents down in far less time than when clogged, I guess I have gotten used to a full DPF.

Loving a cleaned one!

[poyta]

Good work Greg - this all looks very promising. Nice cheap option to get a bit of extra life out of it.

[stormshark]

Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?

Sounds like Benough has the highest Km GT Sport on here would that be right? Im at 130k and considering the long term future of the car although i would like to keep if any others getting higher km with relatively few problems?

[Diesel_vert]

Mate whole point of the DPF was to meet Euro V - perhaps revisit your tech bulletins?? : )

Indeed, the DPF was certainly designed to the Euro emissions standards, but many vehicles could actually meet the Euro 4 standard without one.

But AFAIK, most Euro 5 vehicles are equipped with a DPF.


In regards to DPF cleaning, I found this link interesting:

2011 HDRG Summit - Presentations (http://www.hdrg.org/Presentations.asp)
(Download "An Overview of the DPF Cleaning Market")

Since automated DPF cleaning machines are available for heavy-duty vehicles, and with Greg demonstrating (many thanks!) that DPF cleaning in light-duty vehicles is possible as well (at least for a VW Golf), it would be nice to think that light-duty automotive manufacturers will eventually design an emissions system where the DPF is able to be more easily accessed, serviced and cleaned. One can only hope.

As per the presentation, the DPF cleaning market for trucks is predicted to increase and could potentially mean less cost, less rubbish and less pollution all round, and I'd like to think that people with cars will also benefit from that in the near future.

The technology appears to be all there, so all we need is commitment from the vehicle manufacturers.

[The_Hawk]

My 2010 Multivan seems to use UDS so I can't access the Measuring Blocks :( That said I managed to find an advanced measuring block for the pressure difference of the DPF and it was reading 4hPA on idle and up to about 70hPA or so while at peak revs/boost. This is with 68,000km on the clock.

In the end I gave up digging as I was just going around in circles, but it looks pretty good to me :P

[benough]

Just keep fanging it. I do with mine and at 160,000km, the DPF is fine.

[kaanage]

A definitive write up will be a little while yet, the ECU is still learning and adapting, and I am yet to be convinced I have it totally nailed. It is all looking very good thus far, and my first regen didn't happen till mid 500kms, which is how I remember it used to be. It also regents down in far less time than when clogged, I guess I have gotten used to a full DPF.

Loving a cleaned one!

Epic is the only way to describe what you have done here, Greg. It's threads like this that show the worth of the true enthusiast :)

[Mysticality]

Hmm... I wonder how long the 125CR will ACTUALLY take before the DPF fills up...
Mine's 13 months old and almost at (like 50km off) the 60,000 service. Oh, well... Guess I'll find out!

Excellent write up, by the way!! :)

[Valleyboy65]

Hi newbie here,

Reading with interest your clean out, good job, I have a 2.5 TDi transporter with a few issues and 215,000Klms.

I was just wondering how you know the core is so empty, ''the car is telling me the core is 0.0%'' are you running this VCDS software I have heard about on the forum. Is it good?

John

[h100vw]

Hi newbie here,

Reading with interest your clean out, good job, I have a 2.5 TDi transporter with a few issues and 215,000Klms.

I was just wondering how you know the core is so empty, ''the car is telling me the core is 0.0%'' are you running this VCDS software I have heard about on the forum. Is it good?

John

That's what he has John. Ross-Tech: Home (http://www.ross-tech.com) with the sensor correctly calibrated it does tell you soot loading.

Gavin

[Greg Roles]

Yep I'll add the Ross Tech bit so you guys can sort the loading post washout, but I got it so clean by spending HOURS on the gurney, and washing it over and over and over. On full bore you canlt hurt the core at all, right up close, so you basically go to town, expect to get VERY wet, and the feedback is my DPF is still showing regens down to zero and only 5% ash at a -1.8% setting 5k later. Basically that means the ECU feels it is cleaner than 5 grams!

It's basically back to new, this washout method works, a treat. Car goes FAR better too, less restriction.

Thanks for the kind words, I do like pioneering : )









( when it goes well that is! )

[Greg Roles]

Hmm... I wonder how long the 125CR will ACTUALLY take before the DPF fills up...
Mine's 13 months old and almost at (like 50km off) the 60,000 service. Oh, well... Guess I'll find out!

Excellent write up, by the way!! :)

I would expect CR diesels to last FAR better, as the DPF design is a better one, CR is FAR kinder on soot production and thus the DPF, and the regen process has two valves in the system to ensure they work as intended. All the things that can go wrong in the MKV have been addressed in my humble opinion.

Use good fuel, and stretch her legs when you can, lots of small, start stop trips are to be avoided. Run excellent oil, and a Provent. Period.

[Valleyboy65]

Hi Gavin,


Is it me or does this site time out or drop out? Just lost my post!!

I wanted to thank you for your replies. Have been away on a little camping adventure this week.

VW Campbelltown told me DPF 'worn' and will need all new temp. sensors and new DPS. Van has regen'd approx 3 times in 300 Klms.

Happy days.
Cheers

John

[Mysticality]

I would expect CR diesels to last FAR better, as the DPF design is a better one, CR is FAR kinder on soot production and thus the DPF, and the regen process has two valves in the system to ensure they work as intended. All the things that can go wrong in the MKV have been addressed in my humble opinion.

Use good fuel, and stretch her legs when you can, lots of small, start stop trips are to be avoided. Run excellent oil, and a Provent. Period.

Well that was a little over a month ago, and today she hit 69,700km... :S

I don't spose you could post a step-by-step on the Provent? I've tried searching, but I can't find a nice "What it does, how it does it and how to make it do it"
... Maybe even a little "how much it costs" ;)

I think I remember someone mentioning a high-flow DPF?... Any news on that? :D

[h100vw]

I think you have to click remember me as you log in or you get forgotten. :D

Worn isn't the best description really is it.

As you are in Campbelltown, how about going to Camden GTI and having Matt get the numbers out of it. Then we'll know for sure.

Cheers

Gavin



Hi Gavin,


Is it me or does this site time out or drop out? Just lost my post!!

I wanted to thank you for your replies. Have been away on a little camping adventure this week.

VW Campbelltown told me DPF 'worn' and will need all new temp. sensors and new DPS. Van has regen'd approx 3 times in 300 Klms.

Happy days.
Cheers

John

[volksMuller]

greg , we achieve the same ash load content measured on VAS after using the luiqi moly clean programme....we perform this task for many dealers who follow vw's protocol and say it requires replacement......many a tdi in limp mode with high% blocked filters can be saved .....some whilst in car others need to be removed and cleaned...we charge $395.00 for the task and have hit a home run on EVERY job.....lot less work with the exact same result......just saying there are others way's that work just as well..cheers steve

[benough]

Very interested Steve.

Can I ask how you do it? I imagine you disconnect i from the turbo and spray it down?

[The_Hawk]

Sounds interesting Steve. On one hand I like the much simpler approach, on the other I wonder how it can work as well as striping the whole thing down and cleaning it out.

A quick google turns up this PDF:

http://www.liqui-moly.com/liquimoly/mediendb.nsf/gfx/CD294B9E8ACBAFD0C12579C3003D949A/$file/TI_Pro-Line_DPF_Reiniger_EN.pdf.pdf

If it does indeed work you have to wonder why VW don't have an equivalent cleaning technique rather than a full (and expensive) replacement... being good environmental citizens and all... :P

[volksMuller]

To answer the question ....our tool has probes that are correctly angled to fit through the pressure sensor holes....this allows easy access and easy clean......yes we can disconnect the DPF and wash in situ also.....hope to have a video up to show how its done with the values before and after.....cheers steve

[gldgti]

Nomatter what cleaning agent you use, you can't get rid of the ash without a back-flush and I think thats Gregs main point in this thread. Interesting to see this method adopted right across industry however, as opposed to regular replacement - it certainly seems like the aftermarket is supporting commercial users in creating these semi-regular maintenance schemes where back-flushing is done rather than dpf replacement.

[Greg Roles]

greg , we achieve the same ash load content measured on VAS after using the luiqi moly clean programme....we perform this task for many dealers who follow vw's protocol and say it requires replacement......many a tdi in limp mode with high% blocked filters can be saved .....some whilst in car others need to be removed and cleaned...we charge $395.00 for the task and have hit a home run on EVERY job.....lot less work with the exact same result......just saying there are others way's that work just as well..cheers steve

Good to know someone is offering this as a service, and if you can get similar "new" ash load values then I'd say to everyone to go for this option. I just like doing things 110%.

High flow DPF is still on the cards, but quite a huge task. Catch can kits, and the loooooong overdue Provent kits FAR closer, with me currently pricing medium sized CAD mills.

[Greg Roles]

Nomatter what cleaning agent you use, you can't get rid of the ash without a back-flush and I think thats Gregs main point in this thread. Interesting to see this method adopted right across industry however, as opposed to regular replacement - it certainly seems like the aftermarket is supporting commercial users in creating these semi-regular maintenance schemes where back-flushing is done rather than dpf replacement.

Truck industry would be driving this need mate, given the miles those guys drive.

[gldgti]

Catch can kits, and the loooooong overdue Provent kits FAR closer, with me currently pricing medium sized CAD mills.

Before you commit to that mate, you might want to talk to some lasercutters. My company has a good relationship with another company (they are a big supplier of parts to us) that do lasercutting and CNC folding - which is cheaper and more efficient than milling, and the quality is excellent. (More than accurate and good looking enough for bracketry and flanges).

Lots of lasercut/cnc folding companies around - its a rapidly growing industry that is replacing a lot of expensive machining jobs.

[Greg Roles]

I figured you'd be the last person in the world to try and talk me out of my own mill!!

Billet TDI block anyone ??

[gldgti]

I figured you'd be the last person in the world to try and talk me out of my own mill!!

Billet TDI block anyone ??

Dont get me wrong - having your own mill would be fantastic I reckon!

Theres some great vids on youtube of blocks being milled from billet... one of a W16 engine comes to mind.

But seriously, todays laser is so good and coupled with the CNC folding, bracketry and flanges for exhaust/intake parts are just so cheap and easy. All you need is a CAD program and you can get just about anything made easily.

[Greg Roles]

Hi Greg, just wanted to pick your brain in regards to the DPF wash out thread you posted.
I have a feeling my DPF is on its way out - only got 70,000kms on it but its been tuned from pretty much new. The car goes into Regen pretty much every 3 days now ( just the raised revs, not the light on dash thing ) and the last time I had the light come on I had to do a 20 - 25 minute run along the highway to clear it, its never taken that long before.
Is this along the lines of what you meant when you said you had regens every 50kms or did you have the dash light come on. You mention 30g carbon going to 40g carbon which I have no idea what you mean.

Anyway, with regards to the wash out, you need to blast the water into the opposite flow of the exhaust?
What do you mean by having to wire it together to pull the can back together?
What do you mean by resetting the ash level down to 5grams to be safe? I assume this is somekind of ECU reading ? Is this something that has to be done or can I just cut up my DPF, wash it out, reweld and install again? Will the ECU automatically determine the carbon level?

Finally, how far can I go with the car before its too late and I cant do this flush - I don't want the dash light to go on, unable to clear it and then the car go into limp mode right?
Ie should I do this soon? I'm certainly not paying for a new DPF and not 100% convinced that the DPF delete option is the best choice.


Got this PM, and to save getting this type of question PM several times thought it best to take it public.

The symptoms above are typical of a DPF reaching the end of it's life, in that it is approaching "full". For those with Vag Com, "full" is towards 40 grams on channel 68 under control module/engine/ measuring blocks. The symptoms lone tell you the DPF has little capacity left, as it is regenning very frequently. I intend to write a big article on DPF's as they confuse a lot of people, including those who should know better!

Anyway you need to cut your DPF open, and reverse flush it to blow all the white ash back out of it. Instead of cutting it right out like I did, I would suggest cutting outside the top and bottom canister welds, as you can leave the core wrapped in the steel can. There is a support shelf at each weld to keep the SiC core in place, so cut above and below the welds by a cm or so to just remove the ends.

Go to town with a pressure washer and wash against exhaust flow. You can put a washer nozzle right up to the core and not damage it, but be very careful handling it, as it is very pottery like and can easily crack and shatter like a clay pot. It took me a good hour to get every last bit of fine white ash out, but even getting most of it out will get you a stack of new lifespan.

The car knows how much ash or load is in the core, and can correct for a washed out DPF, but it still makes sense to monitor the corrected ash load on channel 068 as outlined above, and adjust this under advanced coding off the top of my head. I will address all the Vag Com settings in a proper article.

My own DPF has 30k on it since washing it out, and it is still performing as per new. Soot load has gone up about 2 grams from the five I roughly started with. All seems perfect to me.

If you don't do this promptly as your DPF starts regenning all the time, it will indeed reach its end, the car will register the pressure difference as the end of lifespan, and the car will be in permanent limp. It all comes down to what the two pressure sensors "see" and it's hard to trick them.

I will get onto my full DPF write up in the next week or so, as the above poster wont be alone!

[AlexRO]

Off topic but related question ..

Ive got the viezu tune on my car, would I be able to get a downpipe fitted, deleting DPF, and have viezu tune that in and code it so i dont get a CEL ? The only issue that i can think of would be the power increase Id be getting from removing the restriction, and by what viezu have told me, im pretty much running very close to the torque the DSG can handle.. (400ish?)

I just clicked over 100k so I might have to think about things like this in the future :D

[Greg Roles]

I don't support DPF deletes, and am quite sure this is Viezu's official stance nation wide. Very illegal, obvious, and makes your car spew soot like a bus. Not cool.

[AlexRO]

Yeah i completely understand that side of things, I didnt want to go straight pipe, not a fan of soot flying out either. I wanted to come in half way between straight and dpf to get the best of both worlds. May have to keep looking around.

[poyta]

Instead of cutting it right out like I did, I would suggest cutting outside the top and bottom canister welds, as you can leave the core wrapped in the steel can. There is a support shelf at each weld to keep the SiC core in place, so cut above and below the welds by a cm or so to just remove the ends. Go to town with a pressure washer and wash against exhaust flow.

Any chance you could send a photo showing the ideal cutline? Also by keeping the steel surround does it not also mean that you will be leaving the heat sheild around the core? I imagine that this would get seriously soaked during the wash out and the chances of it drying out are pretty slim?

[noone]

Great info, the DPF is one of the main reasons I'd thought I'd never buy a VW with DPF filter (well, the huge costs to replace).

Greg, do you think you would ever offer a swap-service (send me your clogged one, I'll send you a clean one)?

[Greg Roles]

I'm not really interested in washing out cores as it's quite a task and my time is limited, much more interested in perfecting the sports DPF idea which replaces the whole problem entirely. It really is a DIY if you plan it out. I will add a better DIY washout article too, both going up on my site this weekend, as I get a LOT of these questions......

Poyta the DPF hits 700-800 degrees during a regen, and water turns to steam at 100 so it's not going to stick around. Normal DPF temps are 100-400 degrees anyway : )

[Greg Roles]

Here are the pictures I will use for my writeup. On reflection, I think just cutting open the BOTTOM, to expose the full face of the core, to back blast it with a decent pressure washer will be the go, no real need to cut off the top as well. You do need access to the full lower face though to do it properly in my opinion, given the near HOUR I spent with a Karcher 2.54 on full power right up against the back of the core. I tried to see if it was possible to erode the core with the washer, and on my Karcher at least it had ZERO effect. I didn't go stupid though, and ten minutes on one spot "could" erode the surface, so common sense please!

I am sure people doing pressure backflushes get a good effect too, but they sure must use serious flow / pressure!!

The "shelf" that holds Silicon Carbide cores used in VAG vehicles is at the level of weld, as shown by the following pictures. The top section is 1-2mm thick stainless and VERY hard, given it must survive direct turbo outlet temps. The bottom section is MUCH softer.

Cut it open with a 1mm or thinner cutting blade, you need as thin a cut as possible to assist welding it back up. Don't use a grinding blade!!! If you have Oxy etc, then go nuts.

Is a good idea to do an exploratory drill hole, just to find the bottom of the "shelf". If you cut on the lower side surface, about a cm below the weld line, you are very safe, towards the curved bottom edge is a great goal. There is nothing in there to damage, and the stock outlet is pathetically tiny, so don't worry about it. May be different in bigger diesels, the pics below are for the Golf / Passat only in MK V / VI as the bum of the canister is similar in both.

This is my modified high flow DPF canister, and NO it's not proven as yet. It needs to meet emissions, as there is zero future in polluting technologies. Quite a challenge, but I think do-able in Euro V at least.

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/3996010a02fa4a6ebeaf6776d7d70f54_zps30dd-2.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/54142af8b4a148b2b262e919ea109039_zps1685-2.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/205ff2a1b6c54c16881627f03d9bcbfe_zpsfae1-2.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/a933355150a1414b97092d7bd62b6103_zps80ee-2.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/b068e34efae74e9daa0b414b3a44ea11_zps6947-2.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/4f033083f91d4c2888635a5a48ab8a47_zps2482-2.jpg

[Greg Roles]

Also, looking from the back end ( outlet ) of the DPF core, you will see a checker pattern. The open pores are the OUTLET holes, and there is no soot in them, they are basically a cup "facing" out". All the soot is trapped in the alternate "closed" cells, and they are basically cups facing forwards. These closed channels are the ones you want to back blast, but so too forcing water up the open channels will only aid that process.

Just don't make the mistake of focusing on the holes, when you really need to focus on the closed squares.

http://www.vwwatercooled.com.au/forums/images/imported/2013/05/P1010215_zps96d78da9-2.jpg


If you look closely at that pic you can see the soot actually trapped in the edge "outlet" holes that have been resting on the lower "shelf". It's that white ash that is the enemy, and which you need to remove. Nothing, no additive or extended regen can get rid of that oil based ash. A commercial kiln at a few thousand degrees yeah probably......

[poyta]

Thanks Greg. I'll have to give it a go and see how it goes. Can you advise if you need to get the car up on a hoist in order to remove the DPF or would it be possible if I could get the front up on some ramps or stands?

[Ideo]

Great info, the DPF is one of the main reasons I'd thought I'd never buy a VW with DPF filter (well, the huge costs to replace).

Greg, do you think you would ever offer a swap-service (send me your clogged one, I'll send you a clean one)?

You mean any modern diesel? DPF and the huge costs associated with replacement is common to all diesels.

[noone]

Well, probably mate, but I can't see a Jap DPF being 3-4K to replace...

[Ideo]

Well, probably mate, but I can't see a Jap DPF being 3-4K to replace...

I've seen a 8k quote on a Mazda 3 Diesel...

[Greg Roles]

Yeah the Mazda's have a whole extra level of complexity, and I'm only just getting my head around it now. They are a NIGHTMARE compared to the SiC Vag and most Euro cars use, but clever in some ways too. Absolute bitches when they go wrong from what I have been reading.

Yep Poyta I did my whole thing on ramps, but you do need to drop the drivers driveshaft, or at least wriggle it out of the way to get the DPF out, and it has female torx bolts. You need to plan the task ahead of time, and allow a good weekend to do it, the DPF comes out fine, but it's a bit of a chinese puzzle the first time out. Be very gentle with the sensors, easy to upset them. You need to soak them in WD40 for a while before trying to undo them, they can be bloody tight.

Expect skinned knuckles!!

[poyta]

Greg, can you give us some specs the the pressure washer you used? I have a cheapie pressure cleaner but not sure if its ample enough to do the job.

[Greg Roles]

Karcher 2.54 with three pressure settings, I used it on flat out. It's an old model now - but has a max 100bar pressure at 400 litres an hour. They are going to be dead cheap this Queens Birthday weekend at Supercheap I reckon!!

[Harpo]

I have just bought a lovely MK5 GT diesel with only 60K on the clock and the DPF is stuffed.
Have had performed numerous forced regens and completey remove DPF and soaked in moly cleaning fluid over night worked OK for 200 klm intervals for a while and then limp mode. Approx cost so far $1300. :mad:
... anyway Greg is your squiky clean DPF still going good?

[poyta]

I have just bought a lovely MK5 GT diesel with only 60K on the clock and the DPF is stuffed.
Have had performed numerous forced regens and completey remove DPF and soaked in moly cleaning fluid over night worked OK for 200 klm intervals for a while and then limp mode. Approx cost so far $1300. :mad:
... anyway Greg is your squiky clean DPF still going good?

What makes you think the DPF is stuffed? Have you tried some Liqui Moly DPF cleaner? I've had fantastic success with it. Read up on my experience here http://www.vwwatercooled.com.au/forums/f28/liqui-moly-dpf-cleaner-87312-2.html

[Harpo]

DPF is probably OK just clogged with ash. Have soaked overnight in Liqui Moly DPF cleaner.

[ian]

Well I have the same car ,Gt diesel with 58,000 on the clock and have never experienced a Regen, ]Not to my knowledge any how]
I always drive it in a spirited manner, even though i'm retired but ive always had performance vehicles and drive them accordingly,
What would be the first sign of the DFP being clogged?

[Greg Roles]

Regens are happening Ian, every 800kms. It's when the idle raises to 1000rpm, and the car can feel a bit jerky, and induction noises rise. If you had an EGT gauge you could see it more clearly, the car does them automatically at this sort of interval even if it's not needed as a failsafe. Your DPF will start showing signs of clogging after 100,000kms typically and you will start to see DPF lights and notice regens more often as it's capacity decreases.

Yep my renewed DPF is stil going well at 165,000kms now, so it's had a further 60,000kms, I would suggest anyone with a clogged DPF look at getting it professionally flushed, liquimoly DPF cleaners only remove the soot through the Cerium catalyst, but not the ash which is the WHOLE problem, and that needs to be pressure washed back out. There are places that offer this service now.

A proper sports DPF solution will happen, but not in the short term, a lot of testing still required, and I'm not releasing anything till legally approved, so it has to meet emissions. That is unlikely to happen for the MK6 cars anytime soon if at all, but for the MKV it's looking pretty good.

[Harpo]

Feeling inspired/frustrated I proceeded and after a few hours the DPF was out. Hopefully this will be quicker going back in. You need a good set of tools and it was Ok with just 2 small stands under the front. Helps to have a patient mate also to pass tools and wriggle the DPF out.

7464746674657467

I notice that only soot came out and not ash as per Greg Roles. This could be because it was recently had Moly treatment. Greg you are right about the insulation sleeve being fragile as it feel apart after getting wet. Not to sure what to use as insulation now.

My other TDI 1.9 Golf has no DPF and only puffs a little smoke under hard acceleration and this GT has common rail so less smoke maybe? DPF in/out heads or tails.

So in hindsight when buying a second hand diesel car with DPF should use diagnostic equipment to check out clogging to avoid a time bomb OR go for GTI ( non DPF) not GT as fuel consumption and torque is improving eg MK7 GTI

Anyway feeling much better now after knocking the grap out of DPF. The big question now DPF in ( just labour)/out (>$1500 remap ECU)?

[Diesel_vert]

Could just be a dodgy exhaust pressure sensor (G450 if I recall correctly), though you might have already replaced it?

[poyta]

So in hindsight when buying a second hand diesel car with DPF should use diagnostic equipment to check out clogging to avoid a time bomb OR go for GTI ( non DPF) not GT as fuel consumption and torque is improving eg MK7 GTI

You cannot compare a GT to a GTI, two completely different cars with completely different engines. You are right though that a buyer needs to do some investigation when buying a modern Diesel as most if not all of them now have a DPF so eventually all of them will have issues for potential buyers with clogging - having said that its not like there's no issues with a modern Petrol either , the GTi has a lot of common problems for potential buyers too - the important part is that there are solutions to the problem. The washout you performed seems to have worked for Greg, the Moly treatment did wonders for me and for others a DPF delete has been highly successful but remember that a DPF delete is illegal and comes with some very heft fines if caught so if you do go down that path my suggestion is keep it to yourself and don't go posting it on the forums.

[Harpo]

G450 sensor checked by VW once and Euro specialist 4 times. VW quoted approximately $4800 for DPF replacement and install.

[Greg Roles]

OK so my DPF filled up a second time at 200 thou, and it went a lot more quickly than last time in the final stages. Whereas I had a long lead up of increasingly more numerous regens the first time, right down to every 50kms, this second time the car went from doing regens about every 100kms and suddenly tried to do three forced regens in a row ( 50 plus kms of regenning!! ) and went into proper limp.

So I did the old cut and shut a second time, in one day. It's a bitch to remove on a simple jack as you need to wriggle it around and the long tail pipe makes that difficult with limited height, but would be a piece of cake ( comparatively ) on a hoist.

13197

I had no idea how successful this would be second time around, but unlike last time I was on a schedule ( needed the car the next day ) so I didn't bake the core in an oven to get the water out like last time. As such, despite leaving it in the sun and wrapping it in absorbant towels for a good few hours, it was likely still wet. I welded it up, banged it back in, and low and behold car was still going into bloody limp despite any form of reset.

Oh crap. I put my old G450 differential pressure sensor back in thinking that may have been it, but ended up deciding I had to limp it up to VW the next morning to try a new G450. On the way, at a very slow limp speed, it must have cleared the water, and it suddenly decided all was good, and the car reset to zero ash and has been there quite happily for 5 thou now, running like a champion. It always starts off doing regens about every 200kms, but this has been increasing up to 300kms now, as the G450 kind of relearns, so expect frequent regens for the first several or more, always seems to take a bit of time.

SO the moral of the story is if you backflush the core, make sure it is dried out properly, as this will provide the G450 with enough pressure difference to think it's still clogged, well that seems like the situation to me anyway.

[Mysticality]

... Or do a half assed job of drying it out then let it run in the back yard/around the block for awhile!

[Greg Roles]

....which if the G450 sees over 80-90% blockage will not let the car start. I dried mine out quite well ( I thought ) but it was still obviously beyond a 60% reading where the car wants to stay in limp. Slippery slope, bake it in the oven when the missus is out.

[kaanage]

Or put it on the Weber :)

[benough]

My GT TDI is now at 230,000km and the DPF is still behaving normally.

[Greg Roles]

You Sir are what they label an "anomoly" on a bell shaped curve. Even my Yeti running two Provents is showing towards half full of ash at 70,000kms and I'd expect it to clog about 150kms as is usual.

[jets]

My GT TDI is now at 230,000km and the DPF is still behaving normally.

That's good news for the rest of us with lower mileage cars with a DPF. Do you do a lot of highway kms?

[benough]

That's good news for the rest of us with lower mileage cars with a DPF. Do you do a lot of highway kms?

I live in Sydney and use motorways but not all the time.

My belief is that if you flog them, they last. I got 220,000km out of my first clutch too, so it doesn't mean they wear out either.

Also I seldom drive it out of the power band, so below 1700rpm, as below that you don't get the cleanest burn.

Furthermore I only ever put BP in it.

I can't empirically say these things are guaranteed but they have worked for me so far [emoji4]

[Pete N]

OK - so just saw this. DPF clean-out without all the fuss.. The Non-Damaging DIY DPF Home Clean (Diesel Particulate Filter and Catalyst - Ash Blocked / Clogged) - YouTube (https://www.youtube.com/watch?v=LE1boZ3fhLg)
DPF Clean (Utrasonic) at Bosch Milperra (Sydney) works really well - I put my GT Sport DPF though them and it was like new on return..

[benough]

OK - so just saw this. DPF clean-out without all the fuss.. The Non-Damaging DIY DPF Home Clean (Diesel Particulate Filter and Catalyst - Ash Blocked / Clogged) - YouTube (https://www.youtube.com/watch?v=LE1boZ3fhLg)
DPF Clean (Utrasonic) at Bosch Milperra (Sydney) works really well - I put my GT Sport DPF though them and it was like new on return..

Hey
Thanks for posting this.
Was your DPF fully clogged and the car not driving properly, or you just did preventative maintenance?