Diesel Particulate Filter cleaning solutions

[Durb]

My diesel SUV has just returned from the shop with a new DPF as the new one plugged up at 42,000 miles. This filter is plumbed right off the turbos and requires that a lot of the car is disassembled to remove it. The labor and DPF filter would have been in the thousands of dollars had it not been under warranty. This is a sweet engine but extraordinary fuel economy doesn't compute with a staggering bill every three years. I might re-evaluate keeping the vehicle.

My questions are: Have any of you tried the "on vehicle" cleaning methods such as Liqui-Moly, if so, what were your results? Do any of you use the Lucas fuel additive designed to keep your DPF clean?

Our SUV is a grocery hauler and is not subject to many long trips or hard pulls plus there is no manual regen control. I would be willing to try the solutions if I thought they would work. Sure am glad my truck is pre 2007. Thanks for your feedback.

[campigloo]

donn0128 wrote:

campigloo wrote:
A punch and a hammer.

Not only illegal this idea is just plane stupid. Why would the OP intentionally destroy a 2 thousand dollar part?

When done right they run like they’re supposed to

[JALLEN4]

I also have a 2015 ML250 which I assume is the vehicle you are discussing. I have done a lot of research on the same subject and do understand the high cost of the DPF when purchased through a dealer. I would look into finding a qualified independent Mercedes shop in your area or someone who does a lot of Sprint service work. The cost of a DPF replacement should be much less than through a dealer. A number of companies are using the Sprints and are getting over 400,000 miles of service out of them.

From what I have found, once a week might be overkill for a long highway trip but certainly the motor needs to be exercised monthly. As with a number of Mercedes parts, dealers tend to protect the price aggressively and they are kept high. Spending time looking for alternative sources of the necessary parts will be well spent. I have decided to keep mine and to spend what is necessary to maintain it, at least until I can find a suitable alternative vehicle which they are hard to match.

[Durb]

OP here. Other than at idle the engine is completely silent in the cab when driving, we have never detected a regen event. There is only a drive position on the selector, you can downshift with the paddles but it reverts back to a lower gear in short order.

The liqui-Moly is not a fuel additive but a DPF treatment that includes spraying a solvent and rinse through the DPF sensor hole then starting the engine and shooting the dissolved soot in solution out the tailpipe. I was hoping someone had tried the process.

I see on some websites that DPF clogging is even prevalent on the big rigs and equipment has been developed to clean them but requires removal.

I'll try regular longer trips at higher speeds and see how it goes. We really love the vehicle and would hate to give it up.

[Grit_dog]

Ya just gotta drive it. Doesn't need to be under heavy load, but that helps.
By your original post sounds like it's on it's 3rd dpf, but that's probably a typo. Your car should be relatively easy on emissions equipment. Could just have been a freak failure. Is it using DEF like it should?

[donn0128]

campigloo wrote:
A punch and a hammer.

Not only illegal this idea is just plane stupid. Why would the OP intentionally destroy a 2 thousand dollar part?

[campigloo]

A punch and a hammer.

[Charlie_D_]

30 minutes on the highway once a week may not be necessary depending on how you drive but I agree that is the best way to clean the DPF. If there is not a message on the dash saying you are in regen you should see an increase in RPM's while idling. At that time you should try to run highway speeds as soon as possible.

I usually down shift to 4th or 5th when I need to regen. After 15-20 miles I will pull over to check if normal idle RPM's have returned. If not I will run a little further.

After you try it a few times you will be able to set a pattern of how to do it.

[FishOnOne]

When my wife was car shopping a few years ago she had her eye on a certain Jeep Grand Cherokee and when I popped the hood and saw it was a Eco Diesel she didn't flinch when I mentioned it to her that it was a diesel. I knew if we purchased a diesel SUV, that purchase would have been a short lived ownership experience and that we would be going back to a gasser when the emissions system forces your driving style.

OP,
I would be very cautious about using a fuel additive to clean out the dfp as you don't know what ill affects it will have on the fuel system.

[old_guy]

to get the rpm's up drop the transmission into a lower gear and keep it there quite simple really

[spoon059]

Gotta drive it the way it was intended to be driven. My 6.7 diesel is a fantastic truck, but in February we go to Florida for 2 weeks every year. Spend the time on a little Gulf coast island and putter around under 30mph most of the time there. The truck HATES it. I can feel it going into active regen, which is when the engine purposefully burns hotter to burn out the soot. I never drive far enough for the active regen to get up to temperature and end up in regen the entire trip. As soon as I hit the highway pulling the TT, it cleans it right back out again.

This year we are just going to plan to hit the Walmart in the next town over after a week. That should get highway temps long enough to clean it out.

If you don't drive it the way it was designed, you'll be testing a lot of those DPF cleaning additives. Its probably far cheaper to get on the highway and take a roadtrip once a week or bi-weekly, then to pay for additives that may or may not work.

[Humpty]

Once it is up to temp, freeway time at normal RPMs is all it needs.

[mich800]

Durb wrote:
The vehicle is a 2015 Mercedes with a 2.1 liter 4 cylinder, essentially the same engine in some Sprinters but tuned for more power. How do I run it hard, the engine loafs all the time and if I put my foot in it I will far exceed the speed limit in very short order? Are jack rabbit starts sufficient, freeway time at low RPM or choose gears to keep the revs high? Wouldn't high RPMs cause the filter to run cooler?

The reality is there is probably little you could do other than longer drives. What happens is your vehicle tries to go into regen but you quit driving by the time it is complete. It will try again once the engine temp is high enough. But now you have completed your drive and it starts all over again.

The small diesels do not make the obvious sound change (in my experience) to know when regen is occurring. So you end up in this death spiral you are not even aware of.

[donn0128]

You need to find the peak RPM and run it at or near that for at least 30 minutes a week. As a daily grocery getter you definitely got the wrong vehicle.
Get the revs around 2500 on a freway run for 30 minues. More fuel equals more heat not less. Which is needed to burn off the soot. Your dealer should have explained this all to you when you bought it. Guess not.

[Durb]

The vehicle is a 2015 Mercedes with a 2.1 liter 4 cylinder, essentially the same engine in some Sprinters but tuned for more power. How do I run it hard, the engine loafs all the time and if I put my foot in it I will far exceed the speed limit in very short order? Are jack rabbit starts sufficient, freeway time at low RPM or choose gears to keep the revs high? Wouldn't high RPMs cause the filter to run cooler?

[Hammerboy]

I take mine for a joy ride as well if it decides to go into regeneration mode, usually I'll do it on the way home. I live near an interstate so it's easy to do.

Dan