Cleaning DPF in Car Worth It and How

[gmcjetpilot]

I posted this: https://forums.tdiclub.com/index.php?threads/what-does-this-vcds-fault-mean.534780/#post-5869699

I got codes that indicated low flow & efficiency. People went to CRACKED DPF. It could be. I think it could just be full of ash and not cracked.

My question should I try to blow DPF cleaner in there. Try to force regen over and over? I have seen all kinds of techniques.

If I try to clean it what method and solutions are best. DOES IT WORK? Worth trying?

 

[2004LB7]

There isn't any in place cleaning other than a regen. So, without taking it off, that's what I would do. And maybe several and watch the back pressure to see how much it drops between regens to see if it's getting better

 

[gmcjetpilot]

There isn't any in place cleaning other than a regen. So, without taking it off, that's what I would do. And maybe several and watch the back pressure to see how much it drops between regens to see if it's getting better

Negative.... What I have seen, videos (several), pull put the O2 sensor and fill it with cleaner* and put a bung plug in (O2 stays out). You run the car for a period of time. You repeat 4 times. Some disconnect the exhaust pipe at the NOx Cat when doing the static in place runs. Then you drive the car and do REGEN... One video was a DIY'er the other a Pro mechanic using Diesel Particulate Filter (DPF) Cleaning Kit - Liqui Moly LM7946KT1 ($490). I don't want to waste money on that.

The Pro did pressure checks, did very extensive trouble shooting and determined the DPF was shot. Yes he cleared the code but knew the customer would be back.

The DIY did similar things (with not trouble shooting) and used oven cleaner, 4 cans of it. He also got the code to clear, but then I also cleared the code when it first happened. It cane back iin 40 miles (without cleaning or forced Regen).

I think if you just have soot/ash buildup only it may help. I see others take it off (on other vehicles like trucks) and wash it out removed. Again they use chemicals.

In the end however internal crack letting a lot of stuff out and clocking EGR is possible and not uncommon I read. For me? Not sure yet.

Good news. After a long drive (1500) miles I let the CEL show. I cleared the code and soot load was low. The soot was about 5,6g. I did a forced Regen while driving and got it to 1.5g. Too early to tell if it will P0401 and P2002 will come back, clear for now.... BUT.....

Well Now I have
006744 - NOx Catalyst
P1A58 - 000 - Regeneration Required

Not sure if I blew ash and soot out and blocked the NOx Cat? I am not worried at this point. I will just drive it and may try the VCDS forced NOx Cat Regen while driving.

I read another thread and it seems it takes time and miles to clear NOx Cat. I don't feel like taking more maintenance only long drives right now. I will likely not need to drive Heidi (my VW TDI) until later in the week or next weekend. I have another car.

I am getting mentally, financially and emotionally ready to replace the DPF and EGR filter if needed and what ever else, NOX cat or sensors? I like to leave it stock..... I can do the work my self. The cost of a DPF job by a shop is about $3800 to $4000. So I really want to make sure DPF is the issue and not an EGR issue. With only 134K on the engine and DPF typical life is ?????

PS No tail pipe expert but they do have soot and yes bit oily. So I am guessing I will need to fork over some cash soon...

 

[gmcjetpilot]

Well ran NOx regen. Did not go out in 40 mi drive. Drove later back home (most 55-70 mph). I did not regen home but after 20 min or about 20 miles NOx light went out.

No CEL either.

I do have some soot, slightly oily tail pipe. Little doubt DPF is bad dispite my 5 stages of grief. Now moving on to acceptance and $$$$$$$$. Ha ha

 

[MrCypherr]

It will come back. Its cracked. Its common and needs replacement regardless of how many times you clear it and regen it. Theres a whole thread about it.

 

[oilhammer]

The denial people have is just ... I don't know.... funny? Sad? Not really sure.

I have had three so far this week. One was taken away, one still here but will be taken away (he says), the other is getting the work done. Along with the new turbo that finally said "enough" after driving around for nearly a year with the MIL.

I made that thread specifically so people would have a one-stop place for an answer, yet people keep asking. I don't get it. They're junk. They break. They fail. That's what they do. Replace it, delete it, or part ways with the car. Not complicated.

 

[MrCypherr]

I get that its expensive but thats what happens when you own a diesel with this special pieces. I've seen/heard of people spending money to clean them out only to have to spend money to replace it later on. I think its because people dont want to spend the thousands of dollars to replace it only for it to happen years down the road again as well. I dont get it either tbh.

 

[lemoncurd]

Negative.... What I have seen, videos (several), pull put the O2 sensor and fill it with cleaner* and put a bung plug in (O2 stays out). You run the car for a period of time. You repeat 4 times. Some disconnect the exhaust pipe at the NOx Cat when doing the static in place runs. Then you drive the car and do REGEN... One video was a DIY'er the other a Pro mechanic using Diesel Particulate Filter (DPF) Cleaning Kit - Liqui Moly LM7946KT1 ($490). I don't want to waste money on that.

The Pro did pressure checks, did very extensive trouble shooting and determined the DPF was shot. Yes he cleared the code but knew the customer would be back.

The DIY did similar things (with not trouble shooting) and used oven cleaner, 4 cans of it. He also got the code to clear, but then I also cleared the code when it first happened. It cane back iin 40 miles (without cleaning or forced Regen).

I think if you just have soot/ash buildup only it may help. I see others take it off (on other vehicles like trucks) and wash it out removed. Again they use chemicals.

In the end however internal crack letting a lot of stuff out and clocking EGR is possible and not uncommon I read. For me? Not sure yet.

Good news. After a long drive (1500) miles I let the CEL show. I cleared the code and soot load was low. The soot was about 5,6g. I did a forced Regen while driving and got it to 1.5g. Too early to tell if it will P0401 and P2002 will come back, clear for now.... BUT.....

Well Now I have
006744 - NOx Catalyst
P1A58 - 000 - Regeneration Required

Not sure if I blew ash and soot out and blocked the NOx Cat? I am not worried at this point. I will just drive it and may try the VCDS forced NOx Cat Regen while driving.

I read another thread and it seems it takes time and miles to clear NOx Cat. I don't feel like taking more maintenance only long drives right now. I will likely not need to drive Heidi (my VW TDI) until later in the week or next weekend. I have another car.

I am getting mentally, financially and emotionally ready to replace the DPF and EGR filter if needed and what ever else, NOX cat or sensors? I like to leave it stock..... I can do the work my self. The cost of a DPF job by a shop is about $3800 to $4000. So I really want to make sure DPF is the issue and not an EGR issue. With only 134K on the engine and DPF typical life is ?????

PS No tail pipe expert but they do have soot and yes bit oily. So I am guessing I will need to fork over some cash soon...

a word of caution, there is no way on this earthly realm to clean a DPF by spraying anything in the "hot side" of the DPF while also trying to push the airmass through the hotside.

the best youll do is convert whatever soot into ash, the worst that happens is whatever product doesnt burn correctly and THEN you've certified/sealed the fate of the DPF as broken.

the only way to clean a DPF is to reverse the flow through it. water or air. something that isnt very practical to do while the DPF is in the car.
to my knowledge, cleaning a DPF out with water requires the DPF to be baked afterwards to get all the moisture out of the filter medium

water and air requires the use of a cleaning chemical to help loosen whatever ash/soot is left behind that is packed in

edit:
but as oilhammer pointed out, these DPF's are horribly designed and are almost 100% going to crack eventually.
it's a better bet to just replace the DPF while it's out and send the old one in as a core rather than try and clean it; which may lead to another DPF removal.

the best option is deleting it, unless youre looking at it through the eyes of the law/environment. it's a real shame because the DPF is really the only pitfall of these otherwise wonderful cars.

 

[gmcjetpilot]

a word of caution, there is no way on this earthly realm to clean a DPF by spraying anything in the "hot side" of the DPF while also trying to push the airmass through the hotside.

the best youll do is convert whatever soot into ash, the worst that happens is whatever product doesnt burn correctly and THEN you've certified/sealed the fate of the DPF as broken.

the only way to clean a DPF is to reverse the flow through it. water or air. something that isnt very practical to do while the DPF is in the car.
to my knowledge, cleaning a DPF out with water requires the DPF to be baked afterwards to get all the moisture out of the filter medium

water and air requires the use of a cleaning chemical to help loosen whatever ash/soot is left behind that is packed in

edit:
but as oilhammer pointed out, these DPF's are horribly designed and are almost 100% going to crack eventually.
it's a better bet to just replace the DPF while it's out and send the old one in as a core rather than try and clean it; which may lead to another DPF removal.

the best option is deleting it, unless youre looking at it through the eyes of the law/environment. it's a real shame because the DPF is really the only pitfall of these otherwise wonderful cars.

Thanks for the reply. I find it interesting to ask, can't hurt. It was just a question. Did not think it was a great idea.

Now after driving 180 miles with NO FAULT (after forced regen of DPF than NOx cat) I though WAIT is it OK? Then CEL came back. For fun I cleared it and drove 45 miles and CEL came back again today. Same codes. Yes some soot in tail pipe.

I think it is good to exhaust (pun intended ha ha) all ideas.

My issue is not a DPF full of ash, but based on the what I read on VCDS, as you said, and oilhammer said, DPF's cracked. I thought the death of my DPF, would be ash build up not a crack.... I CAN see a good DPF (not cracked) being cleaned OFF the car however, to clear out ash. This is a guess but it is done and often trucks and vans with easy removable DPF from the info I see on WWW. Again DPF cleaning in rear view mirror.

The subject of cleaning DPF is off my radar now. Cleaning is not going to fix a crack.

Parts are on order....