Diesel Particulate Filter
- Thread starter psaboic
- Start date
TheGrove
TDIClub Enthusiast, Veteran Member
- Joined
- May 17, 2006
- Location
- S Central PA (Breezewood)
- TDI
- 2012 Passat SEL Premium Opera Red - Dieselgate Fix, KermaTDI Tune, 2004 Passat GLS Northern Green-RIP
I'm at 136K and have not changed mine yet. I don't know what the loading is as OH did my 120K service. I'll see if I can find it out from the dealer when I have them do my 140K service.
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tdiatlast
Top Post Dawg
- Joined
- Jan 21, 2009
- Location
- Fort Worth, Texas
- TDI
- 2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
^^^and a different engine/cat/DPF configuration. I think the OP was asking about CKRA engine owners.
TurboDieselPoint
Veteran Member
For all intents and purposes, I believe the DOC/DPF configuration for the CJAA and CBEA is almost exactly the same, if not exactly the same as the one attached to the CKRA. I think even the '09 DOC/DPF combo contains exactly the same cores as our CKRA, except the assembly has the cat permanently welded downstream of it. I think the physical differences with our exhaust system start downstream of the DOC/DPF with the SCR system.
That said, OP, from the few high-mileage reports I have read here on the forum, the CJAA and CBEA TDI owers are finding their DPFs are getting full enough of ash starting at about 250K miles to start considering replacement, IIRC. No CKRA Passats have reported having DPFs full of ash yet, and there are a number into the 100K+ mileage now, as mentioned earlier. So our CKRAs should be able to achieve at least 250K miles I would think, but most likely even longer before we require replacement. Since the CKRA has a smaller turbo with greater response and uses SCR instead of relatively larger amounts of EGR, it should produce even less soot over the lifetime of the vehicle compared to the CJAA and CBEA, thus requiring less regens and likely prolonging the life of the DPF even more.
When it does ash up, either take it off and have it cleaned for a couple hundred bucks or replace it. A brand new DPF from VW parts websites tends to run less than $1k. Last I saw was ~$875. Big whoop. In the grand scheme of things, that's not much for a major part that'll last well into the 200-300K mileage.
Folks worry too much about DPFs. They are not a major threat do diesel engines, and chances are the average diesel owner will never have to think about it, drive around its operation, perform any service to it, etc while he or she owns the vehicle.
Enjoy your Passat, free of DPF worries!
TurboDieselPoint
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tdiatlast
Top Post Dawg
- Joined
- Jan 21, 2009
- Location
- Fort Worth, Texas
- TDI
- 2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
Thanks for the very clear post, detailing the differences.
kyle_h
Veteran Member
It's in the VW maintenance schedule to be replaced at 180,000 KM I believe.
I actually took one out today at work, approx 120,000 KM DPF, cat, and EGR cooler all need replacement due to cracked DPF the blew soot through EGR and rest of exhaust.
I actually took one out today at work, approx 120,000 KM DPF, cat, and EGR cooler all need replacement due to cracked DPF the blew soot through EGR and rest of exhaust.
waltzconmigo
Veteran Member
are the Passat DPF's cracking as well? this is the first I am hearing of it.
It is not in the maintenance schedule to be replaced at 180k km or 125k miles. What the maintenance schedule says is at that mileage to check the dpf load and continue checking every service thereafter and only replace when the ash load requires it. The maintenance plan does not specify what that level is though.
kyle_h
Veteran Member
I'll check at work tomorrow but in pretty sure the Canada one says "replace"... anything over 40ish sets a light 44-45 and it's pooched. Grams of soot of course. It's an easy check, mvb 241.
Sent from my iPhone using the Tapatalk app, so that explains the typos...
Sent from my iPhone using the Tapatalk app, so that explains the typos...
tdiatlast
Top Post Dawg
- Joined
- Jan 21, 2009
- Location
- Fort Worth, Texas
- TDI
- 2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
kyle_h: What model car, please?
I like to think I'm informed about the VWoA maintenance schedules, and I've never read/heard anything about a mandatory DPF replacement. If it's clogged, can't be cleared by a regen, then it needs to be replaced.
I like to think I'm informed about the VWoA maintenance schedules, and I've never read/heard anything about a mandatory DPF replacement. If it's clogged, can't be cleared by a regen, then it needs to be replaced.
TurboDieselPoint
Veteran Member
More DPF Ash Info:
Folks in this thread have found that ash tends to build at an average of about 1mL/1000miles, varying a bit depending on driving style and other factors such as oil, etc.
http://forums.tdiclub.com/showthread.php?t=324067
According to this post, the DPF can hold up to 175 mL of ash before it needs replacing, which translates to about 175K miles of service for the average CR TDI before VW apparently thinks it needs replacing.
https://forums.tdiclub.com/showpost.php?p=4035361&postcount=222
...but I'm not exactly buying that the DPF is done after 175mL of ash. There are a number of members in the DPF data thread who have over 175 mL and/or 175K miles--some even over 200K--and still going strong. Plus there's this guy, who went almost 400K without touching the DPF. Even at that mileage, the DPF still seemed to be fine, and outlived other parts of the powertrain like the clutch. This leads me to believe that the DPF can actually still function just fine with more than 175mL of ash in it. This is the why, as I stated earlier, I think the DPF does not have as short of a lifespan as some think they do.
http://forums.tdiclub.com/showthread.php?t=409845
BTW, I just wanted to clarify that I cannot confirm that the DPF cores used wit the CJAA and CBEA are the same as used with the CKRA, but I have reached the conclusion that they probably are, based on studying parts diagrams, schematics, cutaways, pictures of removed DPFs, etc. They look to be identical, and I don't see any reason why VW would put different, yet seemingly identical, DPF cores in the CKRA exhaust.
TurboDieselPoint
Folks in this thread have found that ash tends to build at an average of about 1mL/1000miles, varying a bit depending on driving style and other factors such as oil, etc.
http://forums.tdiclub.com/showthread.php?t=324067
According to this post, the DPF can hold up to 175 mL of ash before it needs replacing, which translates to about 175K miles of service for the average CR TDI before VW apparently thinks it needs replacing.
https://forums.tdiclub.com/showpost.php?p=4035361&postcount=222
...but I'm not exactly buying that the DPF is done after 175mL of ash. There are a number of members in the DPF data thread who have over 175 mL and/or 175K miles--some even over 200K--and still going strong. Plus there's this guy, who went almost 400K without touching the DPF. Even at that mileage, the DPF still seemed to be fine, and outlived other parts of the powertrain like the clutch. This leads me to believe that the DPF can actually still function just fine with more than 175mL of ash in it. This is the why, as I stated earlier, I think the DPF does not have as short of a lifespan as some think they do.
http://forums.tdiclub.com/showthread.php?t=409845
BTW, I just wanted to clarify that I cannot confirm that the DPF cores used wit the CJAA and CBEA are the same as used with the CKRA, but I have reached the conclusion that they probably are, based on studying parts diagrams, schematics, cutaways, pictures of removed DPFs, etc. They look to be identical, and I don't see any reason why VW would put different, yet seemingly identical, DPF cores in the CKRA exhaust.
TurboDieselPoint
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My take on ash loading of the DPF and cracked PDFs is due to people NOT understanding the DPF warm-up mode and DPF regenerations.
The CR Golfs/Jettas control NOX with aggressive EGR tuning. More EGR will put more soot into the DPF requiring more regeneration cycles. A lot of the stress on the DPF is from the high temperatures (up to 1350F) incurred during the regens. A regen simply consists of raising the DPF temp high enough to burn out the accumulated soot. I assume the ash build up comes from any impurities that are not burned off after a regen.
The NMS Passat uses less aggressive EGR tuning because it uses DEF to control NOX. This is also the reason the NMS Passat, a larger & heavier car than the Golf/Jetta, returns better fuel mileage. It's very easy to lower NOX emissions with DEF injection. The NMS Passat DPF still goes through regens just like any other VW CR diesel. Theoretically these regens should be shorter in duration and lower in frequency than the Golf/Jettas due to less soot loading of the DPF due to less aggressive EGR used.
Driving style will have a large impact on the life of the DPF. Short trips will put more soot into the DPF. When one first starts the car when cold, and starts to drive off, when one gets to 3rd gear the car will go into DPF warm-up mode. There is a shutter valve in the exhaust that pinches down and the turbo goes into a high boost condition. This is to raise the temperature of the DPF so it starts working faster. The EGT and DPF temps will quickly climb to around 1150F and the DPF warm-up mode will last around 1.5 minutes. One can feel this hesitation and the best thing to do is NOT hammer the throttle, accelerate slowly. If one makes a lot of short trips and is interrupting the DPF warm-up mode or the regen cycles, I can see where this would lead to ash build-up in the DPF or eventual DPF failure, pluggage, or cracking. The idea of long trips = long DPF life leads right into this previously mentioned thread.
http://forums.tdiclub.com/showthread.php?t=409845
Unfortunately I don't know any VW diesel emission engineers to know how they program the DPF regeneration maps or how much ash loading the DPF is suppose to be able to tolerate before servicing. We also don't know if there is any difference in the EGR cycles between the Golf/Jetta Vs the NMS Passat.
I installed a Scangauge-II in my Passat last week and I noticed regens occurring around every ~250 miles. The regens last around 4 to 5 minutes and the EGT and DPF temps get as high as 1350F (usually during the last minute of the regen) but usually hover around 1150F to 1250F on average.
Coolant temperature during a regen will get as high as 225F, and of course the temp gauge never moves off 190F.
The CR Golfs/Jettas control NOX with aggressive EGR tuning. More EGR will put more soot into the DPF requiring more regeneration cycles. A lot of the stress on the DPF is from the high temperatures (up to 1350F) incurred during the regens. A regen simply consists of raising the DPF temp high enough to burn out the accumulated soot. I assume the ash build up comes from any impurities that are not burned off after a regen.
The NMS Passat uses less aggressive EGR tuning because it uses DEF to control NOX. This is also the reason the NMS Passat, a larger & heavier car than the Golf/Jetta, returns better fuel mileage. It's very easy to lower NOX emissions with DEF injection. The NMS Passat DPF still goes through regens just like any other VW CR diesel. Theoretically these regens should be shorter in duration and lower in frequency than the Golf/Jettas due to less soot loading of the DPF due to less aggressive EGR used.
Driving style will have a large impact on the life of the DPF. Short trips will put more soot into the DPF. When one first starts the car when cold, and starts to drive off, when one gets to 3rd gear the car will go into DPF warm-up mode. There is a shutter valve in the exhaust that pinches down and the turbo goes into a high boost condition. This is to raise the temperature of the DPF so it starts working faster. The EGT and DPF temps will quickly climb to around 1150F and the DPF warm-up mode will last around 1.5 minutes. One can feel this hesitation and the best thing to do is NOT hammer the throttle, accelerate slowly. If one makes a lot of short trips and is interrupting the DPF warm-up mode or the regen cycles, I can see where this would lead to ash build-up in the DPF or eventual DPF failure, pluggage, or cracking. The idea of long trips = long DPF life leads right into this previously mentioned thread.
http://forums.tdiclub.com/showthread.php?t=409845
Unfortunately I don't know any VW diesel emission engineers to know how they program the DPF regeneration maps or how much ash loading the DPF is suppose to be able to tolerate before servicing. We also don't know if there is any difference in the EGR cycles between the Golf/Jetta Vs the NMS Passat.
I installed a Scangauge-II in my Passat last week and I noticed regens occurring around every ~250 miles. The regens last around 4 to 5 minutes and the EGT and DPF temps get as high as 1350F (usually during the last minute of the regen) but usually hover around 1150F to 1250F on average.
Coolant temperature during a regen will get as high as 225F, and of course the temp gauge never moves off 190F.
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kyle_h
Veteran Member
Half the DPF jobs I see at my dealership is due to neglect. Example engine light has been on for a long time, or another shop replaced an egt or pressure sensor and didn't adapt or check mvb 241 to see if a forced regen is required. Either that or it's a city driver so car never gets a regen.
Other half are cracked DPF, mostly on 2009, unfortunate because those are 1 piece catalyst/DPF meaning they're expensive jobs.
Don't think I've ever seen one just plug up on it's own, always an underlying cause. Not saying it's impossible however.
Sent from my iPhone using the Tapatalk app, so that explains the typos...
Other half are cracked DPF, mostly on 2009, unfortunate because those are 1 piece catalyst/DPF meaning they're expensive jobs.
Don't think I've ever seen one just plug up on it's own, always an underlying cause. Not saying it's impossible however.
Sent from my iPhone using the Tapatalk app, so that explains the typos...
hanzonn
New member
Can anyone tell me what the symptoms are when a DPF gets clogged? I have a 2007 German-spec 2.0 liter A3 TDI. Initially, it started "stumbling" at 2,000 rpm (195,000 km). Then the DPF light came on, then the glow plug light came on and I lost a lot of power.
I took it to the dealer - they did a 2,000 Euro injector upgrade, covered by warranty & "cleaned" the DPF. Now, I have no warning lights coming on, but the engine still intermittently stumbles and the exhaust really stinks - very noxious. Power seems normal.
I regularly drive at very high speeds on the Autobahn. Any help is appreciated!
Thanks, Greg
I took it to the dealer - they did a 2,000 Euro injector upgrade, covered by warranty & "cleaned" the DPF. Now, I have no warning lights coming on, but the engine still intermittently stumbles and the exhaust really stinks - very noxious. Power seems normal.
I regularly drive at very high speeds on the Autobahn. Any help is appreciated!
Thanks, Greg
Here in the states Not many DPF cars are of age for plugging up yet. Stumbling is normally fuel related and plugged up exhaust will softly flatten out your power and sometimes make a rig buck if your really into it at low rpm with a plugged system.
TurboDieselPoint
Veteran Member
IMO, increasingly frequent regens is the typical sign of a clogged DPF.