DIY DPF (Diesel Particulate Filter) cleaning (2009 R class- OM642) - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 01-24-2019, 11:03 AM

After watching several videos on DPF cleaning, I decided to give it a try. The majority of the videos did the cleaning with the DPF installed in the vehicle. Others (professional services) clean them with solvents and high pressure. I decided to do a variation of the latter. After removing the DPF from the vehicle, I poured in the cleaning solution (Liqua-Molly from our sponsor), and waited 15 minutes. I then poured in the flush solution. No liquid came out the other end until the flush solution was poured in, and even then only a little. I then used my pressure washer to force water through the DPF (from the out-flow end), thereby removing the soot from the direction it came in. The results were pretty incredible. Massive amounts of black liquid filled the collection bucket. I ran water through until it was clear. A note of caution when removing the DPF- remove the pressure sensor from it's mounting, and disconnect the wire plug, and remove the piping along with the DPF. Don't try to disconnect the piping from the DPF, and leave it there, it is removed along with the DPF.

jay_bob · #2 01-24-2019, 11:20 AM

Thanks! Looks like a good idea for cars that didn’t get a lot of highway to be able to succesfuly regen fully and often.

Xentry or probably any diagnostic with live data, lets you check the delta P on that DPF. This is the sensor that sits in the chassis above the DPF that attaches to the steel lines.

This parameter measures the clog level of the DPF and triggers the regen function.

I will get the computer out on my cars and see how bad the delta P looks. May try this if my cars aren’t getting enough highway to keep them clean.

Dealer replaced the DPF on my 2008 ML right before I bought it.

The 2008 E320 doesn’t show in the history it’s been replaced, but the prior owner put a lot of highway miles on it. I will do a delta P check on it and see how it reads.

Took my 2014 ML350 in for one last catchall fix before the CPO ran out and they ended up replacing the whole entire exhaust system front to back, for free, because I complained of noise from the undercarriage. I got a new DPF “reduction catalyst” and rear muffler.

The W210 has a catalytic filter and these too can get clogged. Unfortunately there is no delta P sensor on these, and if it gets clogged, you get the “banana in the tail pipe” syndrome with no warnings.

pawoSD · #3 01-24-2019, 10:45 PM

Nice! Hoping I don't need to do that for a LONG while on my GLK....

How many miles had it covered to accumulate that much?

Mxfrank · #4 01-24-2019, 11:00 PM

Are you running with or without the EGR valve?

ROLLGUY · #5 01-24-2019, 11:36 PM

Quote:

Originally Posted by pawoSD

Nice! Hoping I don't need to do that for a LONG while on my GLK....

How many miles had it covered to accumulate that much?

The R320 has 143,000 on it, and I suspect it has not been changed or cleaned.

Mxfrank: everything is intact, as it is a CA car. I can only assume the EGR is functional.

ROLLGUY · #6 01-24-2019, 11:39 PM

Quote:

Originally Posted by jay_bob

Thanks! Looks like a good idea for cars that didn’t get a lot of highway to be able to succesfuly regen fully and often.

Xentry or probably any diagnostic with live data, lets you check the delta P on that DPF. This is the sensor that sits in the chassis above the DPF that attaches to the steel lines.

This parameter measures the clog level of the DPF and triggers the regen function.

I will get the computer out on my cars and see how bad the delta P looks. May try this if my cars aren’t getting enough highway to keep them clean.

Dealer replaced the DPF on my 2008 ML right before I bought it.

The 2008 E320 doesn’t show in the history it’s been replaced, but the prior owner put a lot of highway miles on it. I will do a delta P check on it and see how it reads.

Took my 2014 ML350 in for one last catchall fix before the CPO ran out and they ended up replacing the whole entire exhaust system front to back, for free, because I complained of noise from the undercarriage. I got a new DPF “reduction catalyst” and rear muffler.

The W210 has a catalytic filter and these too can get clogged. Unfortunately there is no delta P sensor on these, and if it gets clogged, you get the “banana in the tail pipe” syndrome with no warnings.

I did break the nipples on the pressure sensor when removing the DPF, but have a replacement coming. It is not a bad idea to have one on hand anyway, as the heat makes the plastic brittle. Replacing it makes sense when doing the DPF cleaning.

72junky · #7 09-21-2021, 12:40 PM

Curious if you had fault codes for the DPF or if you did it as a preventative measure. I have a thread going concerning problems with my '08 e320 om642 and would like your thoughts.

Thanks, Brian

72junky · #8 09-21-2021, 12:51 PM

Also would like to know if you purchased the Liqui Moly special sprayer on used your own pressure washer. From the picture it appears it is your machine with your wand. If I'm correct what is the pressure output of your machine. Mine is 4000 psi and worried I will damage the DPF.

Thanks again, Brian

ROLLGUY · #9 09-21-2021, 03:28 PM

Quote:

Originally Posted by 72junky

Also would like to know if you purchased the Liqui Moly special sprayer on used your own pressure washer. From the picture it appears it is your machine with your wand. If I'm correct what is the pressure output of your machine. Mine is 4000 psi and worried I will damage the DPF.

Thanks again, Brian

Quote:

Curious if you had fault codes for the DPF or if you did it as a preventative measure. I have a thread going concerning problems with my '08 e320 om642 and would like your thoughts.

Yes, fault codes for DPF were scanned. I removed the DPF completely, and did in fact use the Liqui Moly DPF cleaner (not the tool, only the liquid). After removing the DPF, I poured the solution in, being carefull to not let any spill out the other end. Wait a few minutes and use your pressure washer to blast out the carbon. There is a metal screen on one end, you can put full pressure against it without issue. The other end has the (ceramic?) honeycomb that can get damaged with the high pressure. If you have a tip that sprays with less pressure, and more volume, it can be used in this end, or from farther away.

Just yesterday I did this job on the DPF in my brother's '07 E320 Bluetec. I scanned three codes after it had a catastrophic intercooler failure (the cooler exploded and was spread along the freeway at 60mph). The DPF code was for the soot content being high, and the other two were boost pressure (or lack thereof) sensor codes from the system being wide open to atmosphere. I assumed the DPF got clogged, and the turbo kept pressurizing the intake system. After cleaning the DPF, and installing an ebay intercooler, the car is back on the road with no issues.

72junky · #10 09-22-2021, 12:29 PM

Thanks for the additional instructions! I'm going the follow your steps and do the same to see if it might be what is causing my limp mode situation. I had a code 2611.001 NOx regen. Lambda vale is too high. Was this the code you had? Curious, how much time should I plan for the R&R and cleaning? I will be doing it on jack stands and a creeper.

WaarrEagle · #11 09-22-2021, 12:37 PM

I explored removal of my DPF recently but ultimately it was not needed. I believe a couple bolts holding it in need to be replaced as they are one time use. Check those in the service manual to verify for your model.

ROLLGUY · #12 09-22-2021, 04:33 PM

Quote:

Originally Posted by WaarrEagle

I explored removal of my DPF recently but ultimately it was not needed. I believe a couple bolts holding it in need to be replaced as they are one time use. Check those in the service manual to verify for your model.

On the E320 and the R320, all the connections are V-band style (or similar), and can be removed/replaced a multiple of times without issue.

ROLLGUY · #13 09-22-2021, 04:36 PM

Quote:

Originally Posted by 72junky

Thanks for the additional instructions! I'm going the follow your steps and do the same to see if it might be what is causing my limp mode situation. I had a code 2611.001 NOx regen. Lambda vale is too high. Was this the code you had? Curious, how much time should I plan for the R&R and cleaning? I will be doing it on jack stands and a creeper.

Soot content too high (explained in post #9). I did other things on the car, but I imagine the entire job can be done in a couple of hours if no problems arise.

jay_bob · #14 09-22-2021, 10:45 PM

Quote:

Originally Posted by ROLLGUY

On the E320 and the R320, all the connections are V-band style (or similar), and can be removed/replaced a multiple of times without issue.

Roll guy is correct, the line band clamps are multiple use.

However, there is one single use castle nut holding the bottom of the catalytic converter on the 642.

The catalyst (KAT) is the first ‘wart’ post turbo that is vertical behind the firewall.

The DPF is the next ‘wart’ that is horizontal in the exhaust line, abeam of the transmission.

If you have a later model with DEF injection, the DEF injector is between the KAT and the DPF.

72junky · #15 09-26-2021, 12:08 PM

While waiting on my delivery from ebay, I got under the car and found my DPF is very different that yours. It does have the band clamp for the front, but, has dual outlets with bolted flanges. I plan on removing sensor in the front of the DPF and unbolting the differential pressure sensor from the tunnel and disconnect it. Bought a new one per your advice.
Question? Did your brother's have dual outlets? If so, were there gaskets between the DPF and the tailpipes? Wondering if I need to source more parts before teardown. Thanks!