Do DPF’s actually wear out?

[Tdimrtwo]

I’ve always thought that DPF’s filter out soot (carbon particles), burn them off during regeneration, but inevitably accumulate ash, which can’t be removed during regen , culminating in a clogged DPF that must be replaced, or at least manually cleaned.

But, I recently came across a video from Australian self-proclaimed “Auto expert” John Cadogan stating that a dpf should last indefinitely, and dpf failures are nearly always the result of other problems in the engine. If the DPF is replaced without fixing the root cause, it will soon have to be done again. Any thoughts on this from the TDI community?

I have a 2015 CRUA with 220k that’s showing a CEL and dpf excessive regens message and occasionally a dpf failed alarm on the display. I’d like to fix it right with any underlying cause, if possible.

Here’s a link to the YouTube video:

Comments?

 

[pedroYUL]

...mildly entertaining...the key word there is "life of the vehicle", which could be 200,000 miles, hence you been at 220k already got your millage's worth.

 

[Tdimrtwo]

I actually linked the wrong video. Here’s the one I meant to include:

 

[pedroYUL]

Gosh, even watching that at 2x it was hardly worth the time.

He was talking, all the time about soot accumulation, never did he mention ash accumulation at all. When the DPF gets full with ash the only way to solve it is to get the ash out of there.
The problem is that these small DPFs are not built to be opened, it is my understanding that only big rigs DPFs are meant to be disassembled and clean of ash.

 

[Tdimrtwo]

Ok, so your opinion is that he’s wrong about a clogged dpf being a symptom not a problem?

 

[pedroYUL]

No, he's right about a clogged DPF with soot is a symptom of something else going on, he's right about that, but over here most people will force a regen first before just changing the DPF.

Now, if the DPF is already full of ash, that is not because something else is not working right, perhaps not using low ash oil. Indeed too frequent regenerations is a symptom of a DPF that can't hold the typical amount of soot, or something else...and every regeneration will accumulate a little ash indeed, so it will shorten the DPF lifespan.

 

[jason_]

I'm guessing the big rigs are able to be opened and cleaned, because the systems are so much larger, they actually have room, as the size of the system allows much much more heat to be dumped into the dpf 5ft away from engine and under the rig in a decent accessible spot. Trying to handle 80,000 pounds is a whole different game then driving around a sedan with a weeks of groceries.

These little weenie car diesels don't make the heat so they pack it right after the wheel.

 

[oilhammer]

The emissions regulations for those big trucks are very different than for passenger cars.

The DPF in your 2015 TDI is not meant to be serviceable, just replaceable. And eventually, it will need to be replaced.

 

[MrCypherr]

Correct me if im wrong, but with regards to passenger cars, the fault Particulate Trap Short circuit to ground. I was told that they build up so much that it causes break inside and have a 'fracture'. Does this sound correct in a way?

 

[oilhammer]

Not sure what that means, but the CJAAs have a common problem where the DPF cracks internally... old news, see it almost every day. Doesn't apply to the OP's 2015 with the CRUA. Completely different setup.

 

[MrCypherr]

I guess thats what they were trying to say where it cracks internally. I was curious if anyone actually had any pictures of the DPF internally to see where it cracks. Completely different yeah. I dont think ive seen DPFs on these 15's go yet really.

 

[oilhammer]

The problem is, in order to "get inside" and see anything, you need to do a lot of cutting... and that alone could cause something to break. It may also be that the substrate simply comes loose from its mounting internally, too. They also want the core back if you are replacing it. I suppose you could look up from the bottom with a butt-scope and maybe see something. Cannot go in from the top, as the catalyst is in the way before you get to the DPF.

 

[Tdimrtwo]

Thanks all who commented, I have a better understanding now. Here’s what I think I know: (please correct me if I’ve missed anything)

1. The Dpf captures soot (carbon particles) in its filter media.
2. When it becomes constricted with soot, periodic regenerations will burn off the accumulated soot, ideally done during highway driving, but can be done at low speed if necessary.
3. During each regen, a small amount of non-removable ash is deposited in the dpf, eventually clogging it and requiring cleaning (if accessible), or replacement (if not accessible)
4. Other engine problems can result in premature clogging, and need to be repaired to avoid repeated dpf failures.

The dpf in my 220k crua is likely at the end of its life, and in need of replacement. Can I assume there’s likely nothing else causing the clogged dpf, since I made it past the 200k mark? I can check the pressure sensor lines and look for turbo oil seal leakage, but probably not much else.

I’m thinking I should go ahead and replace the dpf and hope for the best.

Any other suggestions?

 

[oilhammer]

That pretty much sums it up. The CRUA/CVCA engines were the first and last (for us) of their kind. And we really don't know with certainty what the long-term track record will be, as the data points are still coming in. Not many over 200k miles yet.

 

[pedroYUL]

Wait, but did you get one new DPF with the 2nd part of the recall, the fix after 80k miles?

 

[Tdimrtwo]

No, mine was a 2015 stop-sell that I bought new in 2017, all emissions modifications were done by the VW dealer before it was sold to me.
Please let me know if I’m wrong, but I don’t believe they owed me a dpf under these circumstances.

I’ve gone over 200k without any real issues, emissions or otherwise. Sadly, If my car is typical, it seems like VW finally got it right for 2015, then they quit making it.

I just bought a 2010 CJAA with a bad engine, so I’ll have a good car for comparison.

 

[oilhammer]

There was another part of the fix with the 2015s, but it was time/mileage dependent.

 

[Cuzoe]

No, mine was a 2015 stop-sell that I bought new in 2017, all emissions modifications were done by the VW dealer before it was sold to me.
Please let me know if I’m wrong, but I don’t believe they owed me a dpf under these circumstances.

You are wrong. If you bought a 2015 new in 2017 (as I did) then it only had Phase 1 of the emissions recall which is software only. They owe you Phase 2B (I would expect they have been reaching out to you, although you waiting until you "need" it is the right move). You have until 2050 or 600,000 miles to get Phase 2B done. Not to suggest you could/should wait that long, and it seems you're in need of a DPF right now. But the emissions recall is completely separate from warranty (which for you would have ended via mileage, at 162k).

And getting Phase 2B does not require a CEL or fault codes, although you have them. I'm nowhere near your mileage but my car has no faults so I'm in no rush to get Phase 2B done, even though the dealer is always reaching out to me about it.

Phase 2B includes: Second nox sensor and software, mandatory replacement of Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst (DOC), and Selective Catalytic Reduction Converter

Edit: The mileage dependency @oilhammer is referring to is for the mandatory replacement of Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst (DOC), and Selective Catalytic Reduction Converter, where you had to be over 40k on DSG or over 70k for a 6MT.

There is a long informative thread about the Phase 2 fix here, and they have updated some things. Note that in the past if you got Phase 2 done before those mileage thresholds you would have only got Second nox sensor and software, which they called Phase 2A. There was a time when VW considered that to be "emissions recall complete" which is why I said it was good that you had waited (whether intentionally or not). But they have since changed that so even cars that got Phase 2A before those thresholds can come back and get Phase 2B which includes all the hardware replacement.

 

[740GLE]

IMO he'd need phase 2A and 2B, as he prob never got phase 2A and wiring mods for the other O2 sensor.

And now becomes the chore of educating the dealer of what they should do vs what they dealer wants to do.

IMO you're in Texas right? DFP delete it and motor on, vs dealing with VWoA.

 

[Cuzoe]

Phase 2B is inclusive of 2A. They were only separated because the additional parts did not replacement below the mileage threshold.

 

[Mpaw]

a butt-scope

 

[Tdimrtwo]

Thanks again for all the info. I read through the long informative thread about the phase 2 fix, but there seemed to be a lot of differing opinions about what VW is supposed to do and when they’re supposed to do it. When I bought the car new in May 2017, the dealer said that all the emissions work had already been done, and I wouldn’t need to bring the car back for PH2A or B. They claim that they got the parts early enough in 2017 to do all the mods prior to selling me the car. Is that even possible? When I called them last week, they again reiterated that no outstanding recalls or emissions work needed to be done, so Autobahn VW in Ft Worth doesn’t think I’m owed anything. But, since it appears that I now need a new DPF, I’d like to confirm that the mods have actually been done, hoping that perhaps VW owes me a new DPF as part of the emissions recall. Since I’ve gone 220k on the original DPF, I don’t want to do anything that would keep me from putting a new dpf in and going another 200k. Where is the new additional O2 sensor located? 740GLE indicated that wiring mods to support an additional O2 sensor is included in the PH2B. What is the location of the new sensor? Can I put my car up on jack-stands and confirm that the new O2 sensor is installed? I’m assuming that it’s safe to assume that if the new O2 sensor is installed, then the PH2B mods have all been completed. Last night, Vcds showed my oil ash mass at 84.3 g and a limit of 80.0 g, so it looks like it’s time to replace. But, it’d be pretty nice if VW would pick up the tab.

 

[gearheadgrrrl]

Bought my stop sale '15 TDI in April 2017, dealer did the Stage 1 mod but IIRC Stage 2 mods weren't available yet. So Stage 2 mods probably haven't been done yet on your car, IIRC there's a recall campaign sticker under the hood and VW's TDI website should tell you what mods have been done.

 

[Tdimrtwo]

Almost forgot, about a year ago, I looked into a rawtek dpf/egr delete, I think it was around $2k with a tune. A new VW dpf is about $1,200 from IDParts, so it’s around the same price range. Difference would be I’d still be 50 state legal and emitting less pollutants if I replaced the dpf.

 

[Tdimrtwo]

Just put my VIN into the VW tdi website, shows I’m emissions eligible but only partially completed. I’ll go in next week and try to get them to schedule the PH2 mods.

 

[Cuzoe]

If you go to the last page, or second to last, of the thread there has been a recent update. So even if your car had Phase 2A and/or 2B when you bought it (unlikely but maybe) you would still be able to have the DPF and other hardware replaced as part of the recall.

The change is intended to take care of vehicles that got Phase 2 before the mileage thresholds, which would mean they got Phase 2A only.

In retrospect this makes more sense. Assume we both have stop sale cars and you get Phase 2 at 15k as soon as the dealer says it's available. So they complete 2A (without the DPF and other hardware replacement). I get Phase 2 at 85k so they complete 2B (with the DPF and other hardware replacement). And let's presume the settlement and mandates are intended to make sure our cars are emissions compliant through the lifetime of the vehicle (let's call it 200k).

Well now I'm "50k more likely" to reach that 200k than you but the mandate says VW is on the hook to ensure the vehicle meets emissions compliance through that period. Doing Phase 2A only would be an out for VW and contradict that requirement. And that's aside from unjustly "punishing" you for coming in to have the full recall complete as soon as it was available.

 

[Tdimrtwo]

Thanks for the good info Cuzoe, Looks like I’ve been remiss and haven’t kept up with the emissions work needing to be done. I guess my car probably had the PH1 work done before I bought it, and has been eligible for the PH2 work for several years now. While I didn’t plan it this way, it seems to have worked out in my favor, since I can now probably get a dpf, doc, and scrc replaced for free, and my dpf is at the end of its life. I really thought they said all the work was done before I bought the car, but maybe they just meant PH1 was completed. I’ll take it in first opportunity.

 

[740GLE]

IMO it might be worth your time to call VWoA as the dealer might need some education that is best to come from VWoA vs what "some guy read on the internet".

Play dumb with VWoA, "I received these letters in the mail a while ago, I think this is what it means, but can you clarify it for me?"

It's always best to lead the horse to water, then go in swinging.

 

[740GLE]

Phase 2B is inclusive of 2A. They were only separated because the additional parts did not replacement below the mileage threshold.

Somehow I thought they were different parts, the need to splice in that o2 needed 2A complete, where phase 2b was the rest.

Either way if the dealer touches it it'll get the full treatment.

 

[740GLE]

Thanks for the good info Cuzoe, Looks like I’ve been remiss and haven’t kept up with the emissions work needing to be done. I guess my car probably had the PH1 work done before I bought it, and has been eligible for the PH2 work for several years now. While I didn’t plan it this way, it seems to have worked out in my favor, since I can now probably get a dpf, doc, and scrc replaced for free, and my dpf is at the end of its life. I really thought they said all the work was done before I bought the car, but maybe they just meant PH1 was completed. I’ll take it in first opportunity.

You spoke to a salesman, they prob just cared about the sale as fast as they could as once people became aware the moved fast off the lots (least around here).

The NOS released from VWoA was such a cluster of sharing information of phase 1, gen 1, gen2, gen 3, phase 2, heck as you can read from VW own literature it was muddy.