DanD.

hello all,
Just got my first oil test results, and not sure what to do now.

Report is attached, and here is the Lab Notes:
Odometer: 62K
OIL TYPE & GRADE: Mercedes Benz 5W/30 229.52
OIL USE INTERVAL: 4,000 Miles
MAKE/MODEL: Mercedes Benz 3.0L V-6 OM642

Note:
Universal averages show typical wear for MB's 3.0L diesel after about 10,200 miles on the oil.
With just 4,000 miles on this sample, iron's a bit high. Iron comes from steel parts like cylinders and rotating
shafts, and unlike other metals, it typically tracks with miles on the oil. Iron's also affected by the engine's
use, and city driving, mountain driving, or even extra idling can leave more iron behind, so we'd like to see
how trends build before calling iron an issue. Maybe extra iron is the norm for this engine and the use it
sees. All else looks good for your ML350's engine

What to expect from the car? I'm hopping to keep this car for a little bit longer.
thank you in advance.

Diabolis

I am not sure what type of driving you do, but I see an oil that in some ways looks worn out. The Magnesium and Boron for example (which are part of the detergent and anti-wear additives respectively) are lower than average, which tells me that the additive package is either low to begin with or worn out and the oil is not protecting the engine as much as it can. I'm surprised that there's no TBN (that looks like a Blackstone report and they usually measure it) which would give you another indicator about how much life is left in the oil. If you're planning on keeping the car, keep an eye on the iron and change the oil more often.

Diabolis

One other thing... I see that in one of your previous posts you referred to something you read at some MB service shop site about taking your engine cover off - the same site that apparently advised someone else on here to put in 20W-50 in their ML Bluetec. I would *STRONGLY* suggest that you stop reading things on that particular site. If I were to post somewhere that a 50/50 mixture of canola and olive oil is the best thing for your engine, would you blindly put it in your crank case? Don't believe everything you read on the Internet.

DanD.

Yes, it is Blackstone report.

M-F I do most of the time slow 32 total miles commute to work and back home.
On some weekends we do road trips, highway driving. Monthly on average I do around 2K miles.

Im using MB Oil the part # 001-989-37-01-USA6
MB229.52 Mercedes-Benz Genuine OIl for Diesel Engines
This time oil was changed after 4K
Usually I change oil every 5K but in summer trying to be close to 3.5K.
I'm buying the oil from http://mboemparts.com/

What would you suggest I should do based on this information?

Wfrager

This gentleman makes a very compelling argument for using a different oil from the MB spec.
http://www.stephensservice.com/bluet...ssuesproblems/

I don't think he is some crack pot as he has 50 years of experience with MB service and repair.

When I got my BlueTec the first thing I did was switch to a 20/60 ester based synthetic oil and removed the belly pan. I live in Atlanta, very hot climate.

And don't give me the old adage " do you think you know better than the factory engineers..." so many recalls to show the ridiculousness of that.

It is stories like this that shake me to the core:
https://mbworld.org/forums/m-class-w...i-thought.html

Diabolis

Opinions are like a$$holes - everyone has one. And, with all due respect, I don't think you are in any position to judge anyone's mechanical know-how given the things that you've done to your car. As for the gentleman running the service shop in question and posting his completely misguided ideas and incorrect conclusions, if he has actually been in business for 50 years it might at least explain why he is about 20 years behind everyone else. The technology that goes in the cars has changed a LOT in the meantime, so the things that made sense for the diesel W123s of 40 years ago is in fact very different from what a much more modern and complex engine made in the last 10 years needs.

The only thing that shakes me to the core with stories of the kind that you referenced is that people like you and the naive idiot that was shocked with their $6500 repair bill still exist in this day and age. They don't realize that they have bitten off far more than they can chew, and then moan and b!tch about it when confronted with reality. Cars are wear and tear items that break down. A 6-year old luxury car that was $100K new (at least that's what my diesel ML cost) will require about 5% of its new cost - so about $5K - in repairs *every year in perpetuity* to keep it working as you will have to replace every single part as they wear out and start to fail. Hell, cars are actually engineered to break down and fall apart after a while - it's called planned obsolescence. You buy a used premium vehicle - essentially someone else's discarded goods that for them was a disposable item and treated as such and is furthermore now at the end of the useful life of many of the components - and you expect that you can get years of service from it without putting significant money into it? To add insult to injury, you put in an oil that is so thick that it can't get through half of the oil passages in the motor, has nowhere near enough detergents for all the soot from the diesel, and you put on a tune that basically runs the engine twice as hard as it was designed to be run? Talk about a crackpot...

Diabolis

Relatively short runs with slow stop-and-go driving (i.e. your average work commute) is the most severe use for an engine, in particular diesels. Without getting technical, this type of driving breaks down the oil's ability to protect your engine the fastest and you have to change it more often. The most I'd do in stop-and-go traffic is maybe 5000 km (3100 miles) between changes.

As for the oil itself, I am afraid I don't have much good news simply because of the very design of the modern diesel cars. An oil that is better able to protect the engine itself will by definition shorten the life of the emission control systems because the very same oil additives that protect the engine destroy the exhaust gas treatment components, which are certainly not cheap to replace. Your only recourse without doing any more damage than absolutely necessary to either the motor or the emission control system is to change the oil more frequently before the relatively weak additive package in the ESP oils that MB calls for has been depleted. And, another thing to keep in mind is that the cheapest *fresh* MB-approved oil will protect your engine a lot better than one that costs twice as much but that you only change half as often. If you do oil changes by yourself, buy whatever MB 229.52 approved oil is on sale and just change it every 5K km. The MB oil isn't bad, it's just that after 8000 km (5K miles) it's not going to protect the car nearly as well as as a somewhat cheaper but fresh approved oil will.

DanD.

Diabolis, thank you for your comments, I'm really supersized oil can't last 5K miles, because MB telling to change it every 10K

I'm doing it by myself so cost of changing oil more frequently is not a big deal. This car maintenance plan wasn't created to keep it running, I got that.

nookie

Mercedes has absolutly ZERO clue about oil and what to recommend or do about it for BlueTec
Along with most manufacturers the pressure to stay within emmission guidelines- a new spec or bullitin comes out weekly.

Stephens Service Center has very good recommendation for all bluetec owners. change the oil more frequently!, don't go by service recommendation alone, look at your oil sample.

Diabolis

And here comes the other village idiot to the rescue. I gather you're still sore from having to accept that you were wrong about the LED lights and are now also a tribology expert? The people in your village have been asking for your return... seriously dude.

Mercedes has more knowledge about what the lubrication requirements are for any engine they design and manufacture themselves than anyone else can possibly know. They even have their own oil test sequence as the generic API and ACEA tests and ratings are insufficient for the demands of a modern MB engine, but I am sure you know better.

Now, I am certainly not disputing that there is a requirement for them to stay within emission guidelines and that they are constantly working towards meeting said emission guidelines... which is exactly why they need to come up with more stringent oil specifications every few years that offer *both* as much engine protection as possible and meet said emission guidelines. So, please indulge us - should Mercedes start cheating on emissions they way VW did, or should they just stop making cars altogether seeing as according to your logic those are their only two options?

I have no argument whatsoever with the "change the oil more frequently!, don't go by service recommendation alone, look at your oil sample" advice - it is exactly what I would recommend. I do however take issue with their oil recommendation as all that would achieve is a premature failure of the emission control systems on the Bluetec cars - which are quite expensive to replace - and would furthermore shorten the life of the engine itself as those oils are both far too thick to flow and properly lubricate an OM642 motor and don't have anywhere near the detergent content required to neutralize and suspend all the soot from the diesel combustion.

DanD.

Im going to start changing the oil at 3K miles and new sample. Will see the trend.
Like the car, hope it will last.

Kartergreg

Dan, I don't think your numbers are all that bad. I have done Blackstone analysis at each oil change on my 2013 bluetec and my iron numbers are always much higher than yours. I do mostly highway driving and have been changing oil at about 7000 miles. I have used Mobil1 ESP 10w-40, Total Quartz Ino 10w-30(the worst), and currently Pentosin 10w-40. Last oil change was at 35000 miles and I am due again.

Not sure that changing at 3000 makes much sense to me. Sure the iron number will be lower as there will be less time on the oil, but that does not change the fact there is wear happening. My numbers should be going down, but they are not. May be characteristic of this motor, or there may be a piston/ring seating problem. Then again most people don't do oil analysis and would have no idea. And how many engines these days suffer oil related failures with regular oil changes using quality oil?

DanD.

Agreed, less you know better you sleep, most of drivers newer do oil analyst.

Also agreed, there is wear happening, but with this result I would like to understand how quick is the process, will it last 150K or just 70K, as I just past 60K recently.
Unfortunately OM642 well know for its issues, I didn't do my home work, I just relied on MB and that fact MB makes diesels forever.
If doing oil changes every 3K will add extra year or two to life of the car I will go for it.

Wfrager

Well said Dan, I too am guilty of this.

Diabolis

Kartergreg - the OM642 has an aluminum block, so any iron is likely from the valvetrain. And, a 10W-xx is too thick at startup, which likely is a contributing factor. You should be using a 5W-30 (or *maybe* a 5W-40 if you're towing something heavy 100% of the time, uphill both ways ). Having said that, I agree that the Fe content is not critical or by itself indicative of pending engine doom. Try Mobi1 ESP 5W-30 or Valvoline SynPower MST 5W-30 next time and see what you get on the next UOA. I am not a fan of Total oils, and I don't know anything about the Pentosin - except that a 10W-xx is too thick for the motor.

DanD - changing the oil more regularly will add to the life of the engine, although I too think that you're ascribing way too much importance to the little bit of extra iron in the UOA. The OM642 is not a "lemon" engine... it's no more flawed than any other diesel on the market. One of our clients has a small fleet (~20) of Sprinters with the OM642 and the things that always keep failing are the DPF/EGR, injectors and glow plugs, not the engine internals.

And, stick with MB 229.51, not the 229.52 approved oils. The 229.52 are even more "watered down" in order to meet the emission regulations. Last but certainly not least, find a diesel station with the lowest biodiesel content and try to use that as much as possible. Biodiesel will easily contribute much more to increased engine wear than any differences between the worst and best approved oils, and pumps in the US are regularly using as much as 20% biodiesel content without posting warnings.