Thursday, November 03, 2016

Mercedes MBE 900 Diesel Particulate Filter Cleaning

The emission controlled diesel engine causes a lot of soot and ash build up through out the intake and exhaust system. The sticky GOO that invades literally every square inch of the engine's components has to be removed by way of passive or parked regenerations or physically cleaning off the build up before it's too late.

The video shows us using a household cleaner to soak the diesel particulate filter from a Mercedes MBE 900 diesel engine. This filter was condemned by one of the local shops we took it to for cleaning. They baked it at extreme temperatures to remove as much residue as possible. In this case the test for flow was too low for them to give it a pass.

So our options were to buy a cleaned DPF from the Mercedes dealer for $800.00 or experiment on our own with 'Mr Clean'. In the past we've used it to flush out cooling systems when there's oil contamination or for removing soot from small emission parts but this was something we wanted to try since there was nothing to lose. Mr Clean is an excellent degreaser so our plan was to let the DPF soak for 2 days and thoroughly steam clean it off.

I'm happy to report that since reinstalling this DPF there has been no fault codes for close to three months. The typical 2631 code (turbo boost performance) has not reared it's ugly head for some time now. Since then we've done 2 more buses with the same success. How long until the DPF starts to get plugged up again is hard to say.

They're supposed to be serviced or replaced around 150,000 km according to the Mercedes estimate but that's up for discussion. The plastic drum we used to soak the filter was a used DEF container. One gallon of Mr. Clean is all it takes to get a good strong solution. The soot and ash collected on the filter is liquified so when you use the steam cleaner it comes out looking really good.

Another thing we do is clean contaminated sensors and reuse them instead of spending 50-60 dollars each. Replacement parts for emission controlled diesel engines are expensive so any shortcuts or experiments that work is a bonus :)


Soot Breather said...

Dear John, Thanks for your post. Good to have found a guru! I am actively tracking an issue in inter-city buses in Spain. You can see a couple of short videos here ( ) these soot bursts happen to come from a bus that literally JUST PASSED TWO DAYS AGO the periodic technical inspection, which includes a smoke opacity tests. The affected buses are Scania K-Series (IB), I think K280IB or K360IB. Our area is getting polluted by these buses that pass next to children school every half an hour. Scania happens to belong to Volkswagen group (no comments). Some questions, according to your experience:

- How do you think the bus owner may have passed the inspection?
- Is it technically feasible that they put the particulate filter before the inspection, then remove it after the inspection?
- Can a bus with a particulate filter emit such soot?

Thank you!

Soot Breather said...

Dear John, I liked your post and would like to ask you a quick question. We are being seriously affected by bus soot emissions in our area (it's in Spain), please kindly have a look at two very short videos here ( ). The bus in the videos happen to have passed the technical inspection TWO DAYS BEFORE the video. The inspection includes a smoke opacity test. Wondering how these buses (there are several in this situation) can possibily pass the inspection. These are Scania K-Series IB (K280, K360, etc...):

- Is it technically possible that a bus that is constantly emitting such soot ten hours per day, every day of the month... have a particle filter installed at all?
- Is it technically feasible to install a filter just for the inspection, then remove it?

Scania is part of Volkswagen group (no comments).