# How do you know when DPF is dead?



## diesel (Jun 8, 2013)

So, once at 118K miles and once at 131K miles i needed a manual regen. The one at 118K miles, I am not sure exactly what happened, but at 131K miles, I went from 22-35 grams of soot immediately before a regen started. Since the last manual regen, it's been OK.

So, I am trying to figure out if I have flaky pressure sensors or if my DPF is dying or if it will last another 100K miles issue free. Does anybody know how, exactly, to tell if the DPF is truly dying/dead?


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## Tomko (Jun 1, 2013)

We know that DPF can suffer mechanical failure such as cracking from excessive heat. But you're asking about a DPF that wears out. 

Does anyone know if the FSM addresses the subject?


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## diesel (Jun 8, 2013)

I think one of the primary failure points can be ash loading, and I assume the dealership checked this. With me being the highest mileage person on here, I am the pioneer. I've heard of the VW TDI DPF's needing replaced starting around 100K-120K miles. According to the GM Engineers, the DPF on our cars is supposed to last the "life of the car".


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## Tomko (Jun 1, 2013)

Well, you are bravely going where no diesel brother has gone before. We are all indebted to your leadership. 

And no, I'm not being sarcastic.


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## Cruzator (Dec 31, 2014)

diesel said:


> I think one of the primary failure points can be ash loading, and I assume the dealership checked this. With me being the highest mileage person on here, I am the pioneer. I've heard of the VW TDI DPF's needing replaced starting around 100K-120K miles. According to the GM Engineers, the DPF on our cars is supposed to last the "life of the car".


Obviously, when the DPF is gone, that is the life of the car! (I am being sarcastic - LOL)


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## PanJet (Jun 18, 2013)

diesel said:


> I think one of the primary failure points can be ash loading, and I assume the dealership checked this. With me being the highest mileage person on here, I am the pioneer. I've heard of the VW TDI DPF's needing replaced starting around 100K-120K miles. According to the GM Engineers, the DPF on our cars is supposed to last the "life of the car".


The TDI scheduled maintenance included an "ash-loading" check of the DPF at 120,000 miles, and if it is deemed OK, then every 10,000 miles after that.

One of the primary differences between the VW TDI's (pre-DEF injection) was that since they used no DEF, they had to rely more on the EGR to reduce NOx, thereby producing more soot. From various things I've read, I seem to recall the TDI tended to regen about twice as often as the Cruze in similar driving, but I could be wrong about that. I thought I read somewhere that the Jetta would regen about every 400-500 miles whereas the Cruze in pure highway driving can go significantly farther than that.

Also, from what I understand, the Cruze's DPF is much closer to the turbo outlet than the TDI (up until their new engine came out this last year) taking better advantage of the heat. This is purely my theoretical guessing, but perhaps that enables it to burn off better than the old TDI engine.

These things might help the CTD DPFs to last much longer than the 120,000 miles the prior VW DPFs were slated to last. These are just my hypothesis, but I could be very wrong.


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## KpaxFAQ (Sep 1, 2013)

The main sign a DPF is toast is when you start naturally regening more often than usual eventually leading to a DPF full message that won't be taken care of by manual regen or not for very long. 

Yes with a scan gauge tool you can see total soot load in VW TDI dpf's when is nice. There's an entire thread over at tdiclub where people report their mileage and total ash content of their DPF's. It definitely varies.


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## diesel (Jun 8, 2013)

I wish there was a way we could hook up something to our cars to do a manual regen without the car having to be connected to the "cloud".


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## oilburner (Jun 13, 2013)

diesel said:


> So, once at 118K miles and once at 131K miles i needed a manual regen. The one at 118K miles, I am not sure exactly what happened, but at 131K miles, I went from 22-35 grams of soot immediately before a regen started. Since the last manual regen, it's been OK.
> 
> So, I am trying to figure out if I have flaky pressure sensors or if my DPF is dying or if it will last another 100K miles issue free. Does anybody know how, exactly, to tell if the DPF is truly dying/dead?


I go with lazy sensor issues. 22 to 35 in an instant is not realistic.


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## pandrad61 (Jul 8, 2015)

How do you guys know there is a regen in progress? im at 2,500 miles so I don't think it would need one quite yet. does the display tell you?


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## diesel (Jun 8, 2013)

pandrad61 said:


> How do you guys know there is a regen in progress? im at 2,500 miles so I don't think it would need one quite yet. does the display tell you?


There is no indication. The only way you can tell is with an aftermarket gauge. You can tell you interrupted one if the fan stays on after you shut off the car. At 2500 miles you have had at a bare minimum 2, but more likely 4-5 regens or more.


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## diesel (Jun 8, 2013)

I just re-read my post and I realized I was not really all that clear. I went from 22-35 immediately and the regen did NOT start because 32 grams is the point at which the car will NOT do a regen any more on its own. After 32 grams, the only way to get a regen, you have to go to the dealer. (This is based on what I recall.)


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## diesel (Jun 8, 2013)

oilburner said:


> I go with lazy sensor issues. 22 to 35 in an instant is not realistic.


I wonder if the pressure sensors are replaceable or if you need the whole DPF.


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## pandrad61 (Jul 8, 2015)

Well I always walk in front of the Cruze when I park so I always hear the fans. it has reneged 3 times since owning it. no issues as of no. thanks for the info


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## diesel (Jun 8, 2013)

pandrad61 said:


> Well I always walk in front of the Cruze when I park so I always hear the fans. it has reneged 3 times since owning it. no issues as of no. thanks for the info


Interrupting a regen from time to time is not an issue at all. In fact, I have watched as I interrupted one 3 times and no issues. The problem is when the grams of soot get too high before a regen has a chance to happen. In a completely different scenario than mine, this could happen by several short trips in which the engine and exhaust never get up to operating temp. A regen will not start until the car is very thoroughly up to operating temp.


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## pandrad61 (Jul 8, 2015)

That's good new. I always use my remote start 3 min before I leave. and by the time I park the needle is in its holding temp for a long time


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## Scott M. (Apr 23, 2013)

I think its done when it cant clean itself anymore. I think you may be the one who has to call the abort if you cant confidently take it to work and be sure it will bring you home without going into reduced power. I think maybe the three strikes rule is in order. You seem to have two strikes on your DPF. You seem to be the kind of guy who does his homework. you will make a good decision.


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## oilburner (Jun 13, 2013)

diesel said:


> I wonder if the pressure sensors are replaceable or if you need the whole DPF.


yes they are replaceable.


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## PanJet (Jun 18, 2013)

pandrad61 said:


> How do you guys know there is a regen in progress? im at 2,500 miles so I don't think it would need one quite yet. does the display tell you?


Like was mentioned before, the only certain way to tell is an aftermarket gauge, although there are some telltale signs, namely a significant drop in instant mileage readings for about 10 minutes or so. If my cruise is set to 55-65 on a fairly level road and I'm consistently seeing 35 or lower MPG, it's usually in the process of a regen.


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## Kexlox (Nov 4, 2014)

PanJet said:


> Like was mentioned before, the only certain way to tell is an aftermarket gauge, although there are some telltale signs, namely a significant drop in instant mileage readings for about 10 minutes or so. If my cruise is set to 55-65 on a fairly level road and I'm consistently seeing 35 or lower MPG, it's usually in the process of a regen.


You can tell if you switch to the ECO gauge on the DIC that has a bunch of stacked boxes to show your instant MPG, and take you foot off the accelerator so you are coasting. It will show 99MPG as your instant MPG, but if you are doing a regen the top box will be empty. If you aren't doing a regen, all the boxes are filled.


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