We have a 2010 ML350 Bluetec with 158k miles on it currently. It seems to be exhibiting the same symptoms that a few others are experiencing, including high oil consumption, poor fuel economy, and P2458 and P2459 codes.

Here's my tale of woe...

A few months ago we started getting a P2459 DPF Regeneration Frequency code. I didn't worry about it much because we mostly do city driving, and I figured we just weren't getting it out on the freeway enough.

But then I started noticing that the low oil light warning was coming on more frequently. When I started tracking it in January it seems to now be going through a quart of oil every 200-300 miles.

I just took it on a 600 miles trip in one day and was super excited that the computer was showing it was getting about 30.5 MPG over the trip. But at 400 miles the low fuel light came on, which didn't make sense. When I filled it up and calculated my mileage from the receipt I got closer to 22 MPG. And while I don't expect the internal computer to be 100% accurate, to be off by 50% is pretty bad.

When I checked the codes yesterday after the trip I now have a P2458 DPF Regeneration Duration code, and the P2459 code shows as a historic code.

So I started looking into this more yesterday and found DaveSVO's post: https://mbworld.org/forums/diesel-fo...-solution.html

Please forgive me if I'm not as well versed on the diesel issues as I should be, up until a few months ago our ML350 has been pretty reliable which allows me to wrench on my vintage Alfas, which are much easier to work on (and fit into my small garage!)

I assume the DPF is getting clogged with oil and can't clean itself. But the engine keeps requesting regen cycles, which is increasing our fuel usage and decreasing our fuel economy. It's probably also diulting the oil and making it easier for the oil to burn. So we are stuck in this vicious cycle.

I'm on the list to get the emissions recall, but like everyone else waiting for an EGR valve. I assumed the new DPF would solve our regen issue, then I could figure out if the oil consumption was ongoing or related to the DPF issues and deal with it accordingly.

But since I have no idea when Mercedes is going to have EGR valves I'm trying to figure out how to keep this thing running until it can be fixed, or we can get the recall and sell it. It's supposed to be our tow rig, and I can't imaging trying to go anywhere with it at the moment, especially with a trailer.

So here's my plan. If anybody hash any suggetions on what else to do I'd be grateful.

1. Change the oil and filter
2. Check the turbo inlet and clean out the oil
3. Try to figure out how often the regen cycle is running. I have a decent Autel scanner, I'm not sure if that will work but that's where I will start. I'm open to other suggestions.
4. Figure out how to clean the DPF so it stops running the regen cycle so frequently. Ideas are a manual regen, using a cleaner in a bottle, or removing it and sending it out. Would love suggestions here as I can't afford to wait for Mercedes to replace it.
4. Add an oil catch can to catch the excess oil and keep it from going through the engine and clogging the DPF again? I was thinking of doing this before the oil consumption got bad. Maybe it's a waste of time?
5. Hope the recall is ready at this point?

FWIW we bought it 4 years ago with about 134k miles. It was a fleet rig for most of it's life and had regular oil changes, I'd have to check the frequency. I changed the oil at 134.600 miles, 143,291 miles (at the dealer for other work), 147,678 miles and 152,630 miles. I use Mobil 1 0W-30 that meets the MB 229.52 spec.

I live in an area with emissions testing so I can't delete everything. At 150k miles I also don't know if I want to put in a new engine like DaveSVO did, although with the price of cars these days that's certainly an option. The $3500 rebate would pay for half of it.

Thanks for any help and advice, and again I apologize for not being very active here. I spend more time over on the Alfa forums, since this ML350 rarely needed work after I sorted the few niggles when we bought it.

 

So you do have AEM coming? Can you park the car till the dealer is ready for it?
Troubleshooting and fixing can be long and painful process,
Can you pull regeneration history?

 

I am on the wait list for the AEM, I called last week to find out what's going on and was told about the EGR back order.

I can park it for a few weeks as we have another car, and we have a vacation coming up once kids are out of school so we won't need it for a bit, but I'd really like to be able to use it this summer as it's our tow vehicle for our trailer.

I know troubleshooting can take a long time, which is why I'm hoping Mercedes can get it in for the recall. If the recall was done I could put an oil catch on it until I figure out the oil issue, whether it's blowby, or the turbo seal. If it's the turbo seal I can fix that and keep going. If it's blowby we will probably trade it.

But my big frustration is potentially losing a whole camping season because of the EGR backorder.

 

You can always rent another vehicle for vacations.
Lot of things those days can bring frustration, but I think spending your time and money on something that WILL be covered by modification and warranty is not making much sense.
Bare in mind you have till August 1 to file the AEM claim.

 

Isn't unti October first to file the claim?

 

Yes I believe you have until October 1 to file. But I filed back in March and it's super frustrating to have a car with a bunch of problems that I can't really drive because the manufacturer can't get the parts they need.

As I mentioned before this is our family car and tow rig. You can't easily rent a truck to tow a trailer, it requires setting up brake controllers, weight distribution hitches etc. And most rental companies don't want to utowing with their SUVs.

Has anyone heard any updates about when the EGR valves will be available?

 

I believe the deadline for filing reimbursement is October 1, but can't find the page right now. AEM and following warranty don't have expiration time.
After some hassle I have appointment coming on Wednesday, when person scheduling appointments has no knowledge about the job.
Hopefully they found the parts, as they have been playing games with me.
EDIT. found the page
https://www.mbbluetecsettlement.com/dates

 

I have gone from #45 on the list to #10 a week ago. I just want to get it done early enough so I have enough time to file the claim before Oct 1.

Do you think MB is dragging their feet on the EGR valves?

 

Not likely. Each dealership is independent, so nation-wide conspiracy is not likely.
The parts come from Germany anyway. If my appointment next week will not work, I am calling MB hotline. They have to give some answers.

 

So MB finally updated our ML350 in August. We picked it up on August 15, and we have put 150 miles on it since then, but it won't run the Particulate filter monitor, or the NMHC Catalyst monitor.

I"m seeing some failures for test on O2 sensor Bank 1 #2, and bank 1 #3. But my scan tool isn't smart enough to know what those test are.

Anybody else have these issues after the update? Our registration is due soon and I'd love to get these done. But my guess is that either MB didn't update the software properly, or it's still got bad parts or old parts that aren't playing nice with the new parts.

No major changes in driveablily, but then I don't drive it hard. Or often. I'm still monitoring the oil usage to see if it goes down.

I did get an oil analysis when I changed the oil this summer and they detected high fuel levels in the oil, so I will be changing the oil more frequently until I know everything is working properly.

What a pain.

 

Another update. The NMHC Catalyst monitor finally ran and passed. But the PM monitor hasn't. We're up over 300 miles since picking it up, and will put another 200 miles on it this weekend. So hopefully it will run soon and I can go get it smogged and registered.

In other news the steering shaft seems to be binding a little, so that's the next job. Seems to be totally unrelated to the other work, I probably just didn't notice it with the other issues.