DPF wisdom?

[DavidS]

Wisdom??

I’m a newbie so please bear with me.


2011 Jetta TDI, 6spd manual, 126k miles, fix was done, out of warranty, all stock emission system. (originally purchased used in 2019 from VW with 60K miles, been a trouble free drive)


We had the CEL light come on, and on occasion the glow plug light. Took it to what seems to be a reputable garage, (specialize in VW Audi, great communication, reasonable prices) over the course of the last few months. I can post the transcripts of the work that the garage did if that would be helpful.

I have read a lot of threads on this forum and am overwhelmed with knowledge base and possibilities. (the threads seem to agree with the garage's diagnoses that the DPF is bad)

My questions

What will happen if I just keep driving with a bad DPF?


They quoted $3,620. To change out the DPF & EGR filter is that reasonable for the work?


Other options , wisdom or comments?

Note:
I live where there are no emission inspections. (there isn’t even state safety insp)

thank you in advance!

Dave

 

[AverageAndy]

They quoted $3,620. To change out the DPF & EGR filter is that reasonable for the work?

That could be reasonable for your area, but I'm cheap and hitting a pothole and doing the work yourself would only cost 1/3 of that. Plus you can sell the DPF/cat for a ~$400 "rebate."

 

[Tuheeden]

As mentioned, if you keep driving it will get more and more clogged, which will increase the temperature and back pressure on the turbo until the turbo fails.
Additionally that heat and back pressure is cooking your oil and that can cause additional issues.
A Delete, while still likely illegal where you live, would cost about $900 for the exhaust system and $600 for a tune BUT you would have to do it yourself (No shop will do it). Just sharing the math that many consider

 

[DavidS]

The work doesn't scare me.

So this brings up two more questions, as look for potholes.....
1. as I snoop around for "solutions" I see that there are a many different companies offering off road solutions. I am not looking for a big performance boost, just a quiet running trouble free ride. Any suggestions aftermath, rawtek, tditunes?

2. I am in eastern Ohio if the the car moves to Pennsylvania in the next year, I know diesel cars used to be exempt from the emission testing in PA, but I don't know if that is still true? Can anyone from PA help me with that?

If these questions are out of line here feel free to remove them, as stated in my original post, I'm a newbie.

Thanks for the wisdom!!
Dave

 

[Bob S.]

BRM down pipe sourced from a used auto parts vendor and an appropriate adjustments to configure the engine controls to the OEM VW exhaust component.

 

[Tdimrtwo]

I just purchased a 2011 JSW 6 spd with a bad DPF, so I’ll also need to replace or delete very soon. But I’m confused about something. Tuheeden and turbodieseldyke say if I keep driving it with a bad DPF, it will clog, cause backpressure and destroy turbo then engine. But I believe oilhammer says the media cracks, allowing soot to escape Dpf confinement and soot up the tailpipe. At first blush, those seem contradictory to me. So what actually happens when you have a bad Dpf and how does it destroy turbo then engine if you don’t fix it? Thanks in advance for any enlightenment you can share with me. I also have a 2015 which has had 2 Dpf replacements under warranty, so I’ll have to do it eventually as well.

 

[Tdimrtwo]

Thanks turbo, I figured there had to be something I was missing. Want to know what I’m getting in to before I jump in the deep end.

 

[MeanGeneMoreau]

I was under the impression that a clogged DPF will also severely damage the engine, because of the excessive back pressure…is this right?

 

[Tuheeden]

I was under the impression that a clogged DPF will also severely damage the engine, because of the excessive back pressure…is this right?

The DPF starts with being clogged, then it fractures internally which can relieve a bit of pressure but then it continues to clog.
So the back pressure is bad but the real killer is the heat that is caused by the back pressure will cook the turbo and even cause damage to the exhaust valves or cylinder.
I short: yes you are correct
Driving it for very long will eventually end in a big repair bill

 

[JJ1C13]

Is there a definitive way to know your DPF is clogged or cracked?

 

[P2B]

Is there a definitive way to know your DPF is clogged or cracked?

If the tailpipe is not white-glove clean the DPF is cracked.

 

[Rob Mayercik]

If the tailpipe is not white-glove clean the DPF is cracked.

I'm guessing this is only an accurate test the first time a car's DPF fails, unless you to wipe out the tailpipe after each time you put a new DPF in?

I don't have a DPF-equipped TDI, but I did get to wondering about this...

 

[P2B]

I'm guessing this is only an accurate test the first time a car's DPF fails, unless you to wipe out the tailpipe after each time you put a new DPF in?

Yes, a thorough cleaning of the last few inches of the tailpipe is best practice when installing a new DPF.

 

[Rob Mayercik]

Stands to reason, but sometimes I like to ask anyway because you never know.

I'm surprised nobody's come up with a "serviceable" DPF that could be removed from the car and effectively cleaned, but then I don't know what the actual filter process is (I was thinking the soot/ash builds up as a powder or similar, and a clogged filter if opened up looks like a toner cartridge from a laser printer or copier, but I could be wrong).

 

[P2B]

The DPF cleans itself quite effectively - until it cracks. Why would you want one that has to be removed periodically?

 

[Rob Mayercik]

I was under the impression that the cracking is caused by the DPF plugging up, so I thought if there was an easy way to "dump out" the soot/ash it would make the thing last longer, especially since they seem to always crack eventually and they're extremely expensive to replace.

(by the way, what are they made of that makes them so pricey, and are there no less expensive alternatives?)

I'm looking at this from the outside (ALH owner), so I probably don't fully understand the processes at work.

 

[P2B]

I was under the impression that the cracking is caused by the DPF plugging up

It's caused by the heat cycles involved in regeneration.

 

[Rob Mayercik]

Oh, ok. Thanks for clearing that up.

 

[LordZedd]

It's caused by the heat cycles involved in regeneration.

This is correct. In my fleet of transit buses, the early active regen DPF series (2008) frequently cracked because they were programmed to full regen every 24 ECM hours no matter it's needed or not. The earlier passive DPF's (2006) never cracked except with an injector or turbo failure. Later (2013+) very rarely crack because they regen only every 144 ECM hours or as needed.

 

[jesswithawagon]

Question related to this, my dpf warning is constantly on now... My mechanic said he changed someone else's with an aftermarket one for $800. Anyone have experience with an aftermarket dpf working? For how long? What kind of it actually worked! I'm not in a place to drop 3k but if it keeps my car alive I want to know what I can do!

 

[P2B]

My mechanic said he changed someone else's with an aftermarket one for $800. Anyone have experience with an aftermarket dpf working?

No, because aftermarket DPFs do not exist. Your mechanic was referring to a delete kit.

 

[jesswithawagon]

Would that cause it to fail inspection? I live in Massachusetts... Was previously told no mechanic would do a delete... I'll ask him

 

[AverageAndy]

Would that cause it to fail inspection? I live in Massachusetts...

If they do visual and look for a DPF that isn't there then it will fail. If they do OBD2 plug in and you don't have a tune with readiness set then it will fail. If they do a tailpipe sniffer then most likely it will fail.