Recurring DPF failure 2014 TDI Sportwagen

[Mike Morriss]

We bought the car on 17 or 18 Jan 2018 after "Dieselgate". VW had bought the car back from the original owner and applied their "fix".

In June 2021, the DPF failed and was replaced under warranty by a VW dealership with a good reputation. Miles 99,848 "on the clock." My cost was $0 but there was some inconvenience, since we live about 100 miles away from the shop. They gave us a loaner car to use while they did the work.

In May 2023, DPF failed and was replaced by the same VW dealership. Miles around 113,000 "on the clock." My cost was $0 but there was some inconvenience, since we live about 100 miles away from the shop. They gave us a loaner car to use while they did the work.

I drive the car around our small city regularly but go on road trips, where I cruise at abound 80 MPH for a little over an hour going to the destination and then again, when returning home.

What can I do, if anything to stop this recurring DPF failure?

 

[jetta 97]

One thing it will help is avoid short trips and to much idling, but in general I think all cars will have short life on DPF due to software update and lof of heat producing in exhaust system .

 

[oilhammer]

You'd need to better define what "failing" is, as these rarely fail in a sense of the get laden with ash beyond normal regen parameters. The fail mode is usually a crack and the soot bypasses and manifests itself first as a plugged low pressure EGR tube.

 

[Mike Morriss]

Thanks. That is sad news. I don't put much idle time on our Sporty and I thought the 80mph runs would go a ways toward keeping the DPF in working order. Are there any mods recommended to stop this such as getting rid of the DPF completely, etc.?

 

[Mike Morriss]

You'd need to better define what "failing" is, as these rarely fail in a sense of the get laden with ash beyond normal regen parameters. The fail mode is usually a crack and the soot bypasses and manifests itself first as a plugged low pressure EGR tube.

I don't know how I can better define the failure. I recall someone saying something about cracked back in 2021. The codes I got in 2023 were
P2002, Particulant Trap Efficiency Below Threshold
P0401, Exhaust Gas Recirculation Flow Insufficient Detected

 

[oilhammer]

Yep, that's a cracked DPF. Sooty tailpipes are the easy quick way to verify.

 

[Mike Morriss]

Yep... had sooty tailpipe for sure :-( Sometimes after I stop the car the fan keeps running when I think it shouldn't. Could be doing a re-gen. Any advice about what I might do to help things when I notice that? Maybe drive it a while?

 

[Mass. Wine Guy]

Have others had similar problems? Do the 2015s also suffer from this? Or was the system upgraded by then?

Wouldn’t long highway drives at high RPMs burn out the potentially problematic soot?

 

[Mike Morriss]

Have others had similar problems? Do the 2015s also suffer from this? Or was the system upgraded by then?

Wouldn’t long highway drives at high RPMs burn out the potentially problematic soot?

I can't answer about 2015s.

It appears long drives at high RPMS (80mph in 6th gear) might burn out soot but don't fix cracked DPF, which appears to be my recurring problem. :-(

 

[Mass. Wine Guy]

Definitely sounds like a defective design.

 

[Mike Morriss]

Definitely sounds like a defective design.

I agree. Sad that I have one and don't know if VW is gonna come up with a good fix or not. :-(

 

[Mass. Wine Guy]

Probably not. But they should pay to replace it.

 

[Lightflyer1]

Best way to deal with regions is to get a gauge so you can tell what's going on. VagDPF is one that I use with my Android phone and an OBDII dongle. If you know that one is needed then you can just keep driving and let it complete. The problem is short drives and not letting it complete a regen. This won't fix the broken DPF but it is a good way to keep aware of the regen situation. Driving at 80 mph won't do anything if it's not due for a regen.

 

[Mike Morriss]

EVERY TIME it fails??? :-(

 

[N C Brown]

> Sometimes after I stop the car the fan keeps running when I think it shouldn't. Could be doing a re-gen.

Chiming in because I also get exactly this - the fan activates after turning off the car. No idea why.
Sometimes I just let it run, other times I restart the car just to silence the fan.

Apologies in advance, I don't have much deep TDI know-how to share, only my ongoing misadventures.
They do seem somehow temperature-dependent. Unfortunately, when I bought my Jetta it was January!

 

[Mike Morriss]

Thanks and good luck!

 

[Lightflyer1]

Generally speaking, when the fan keeps running when you turn it off it means you interrupted the regen.

 

[Mike Morriss]

So, will starting the engine back up again and letting it run for a while let the regen finish? I have noticed idle RPM is higher at times, maybe when regen is running. It usually idles at about 800 but closer to 1000 sometimes.

 

[Lightflyer1]

Not usually just sitting there. Having a means to monitor it is needed if you actually want/need to track your regen status. This is what I use.

 

[oilhammer]

The issue with the CJAA engine is that the DPFs internally crack, the regens really are a secondary issue. These hardly ever fail any other way other than the internal breaking. And while monitoring and being sure a regen completes as intended is certainly not a bad thing, it still isn't going to wave a magic wand over a lousy fragile design with repeated failures. Unfortunately, the only magic wand here is a delete. And no, VAG isn't going to "fix" this problem. It was already a problem before Dieselgate, and their "fix" for that just made it worse. They're just kicking the can down the road, getting all these cars out of warranty, (at this point most of them already are) and at some point I'd bet there will be no more new parts available for these at all, so your ONLY choice if you want to keep driving the car is to delete them. I doubt any aftermarket company is going to step in to make something like this.

 

[borninabus]

my DPF has 80K miles on it. all of which were racked up while using a stage two tune from malone. i don't doubt that the tune has helped keep my soot levels in check and in turn is helping my DPF last. i try to let regens complete when i notice they're happening but other than that, no special treatment or monitoring on my part--just driving. to the OP: may i suggest a non-delete tune.

i actually like my DPF equipped "clean diesel" AND my sunroof, but i'm an outsider around here when it comes to these things

 

[oilhammer]

I like my sunroofs, too. And I hate smoky diesels. I'd love it if the DPF-equipped cars were less troublesome, AND I'd love it if the regulations were more diesel-friendly and not have such draconian NOx limits so we could actually have a bunch of clean running sootless high MPG refined diesels to choose from. But, we can't have that.

Feel free to buy all the giant gasoline V8s you want to, though.

 

[Mike Morriss]

Thanks for all the responses. Please tell me more about delete.