dave2001auto

dave2001auto

dave2001auto

Micah / AF1 Rac

benzslo

Your thread title makes it sound as though there is some systemic issue with the on642 engine. I can tell you as someone who strictly works on Mercedes diesels, 90% being the om642 engine, thousands every single year at the dealer level, there is no such flaw and good luck proving it because it's just not there. I didn't read more than the first post here because it's a waste of time. I could go on and educate you on the subject but it eould fall on deaf ears.
Also just out of curiosity why would you feel as though Mercedes is obligated to buy you an engine when it is outside of the agreed upon warranty of 50k miles? Don't bother replying it's more a rhetorical question and I won't bother checking back here for the internet experts reply. I understand being disappointed but I can all but guarantee what caused your failure was outside of Mercedes control and was likely an outside influence of a number of scenarios I've seen and dealt with first hand. Even if it was some kind of freak part failure leading to catastrophic damage (it wasn't, I'm being hypothetical), that is why the manufacturer has black and white boundaries on warranty boundaries. If the manufacturer wants to take care of a customer and cover something that is outside of warranty as a gesture of Goodwill, they can, but are certainly bot obligated to do so.
And your case really has no merit being that there are no inherent design flaws with this engine leading to failures. None. If used and serviced by Mercedes standards, these engines will run forever, periis. Something happened to your engine that was outside of Mercedes parameters I can assure, I could speculate on a number of scenarios based on what I have seen first hand through my own experience but speculation gets you nowhere.
It's an unfortunate situation for you for sure but to come on here with your attitude and stance on something you kniw nothing about, with an entitkemeen attitude on top of it, sorry I have no sympathy for that. Good luck proving your case in a court of law.

Glyn M Ruck

Thanks. Nobody has ever explained it so clearly before. Amateurs can speculate all they like. And a little knowledge can be a dangerous thing & lead to erroneous conclusions. There is nothing wrong with fully approved Benz lubricants sold in the US either. We have churned the rest multiple times so there is no point in repeating it.

There is nothing wrong with the OM642 engine.

Out of interest one of the best technical minds & a moderator on this forum has just pulled the trigger and bought a CPO 2014 ML350 Bluetec with 38K miles.

smiledr996s

Glyn M Ruck

I'm a tribologist. Every diesel OEM is giving away a little engine protection to extend emissions control device life at the present state of the art. Benz is right at the cutting edge of emissions control. Us oil companies are likewise maximising the use of ashless anti-wear additive technology in 229.51/52 type products that have an ash clamping limit ~ in this case <0.8%. You can use 229.5 oil in this engine and it will do a superior job but this should only be done accepting that you will shorten the life of the emissions control gear. Asking by how much is like asking how long is a piece of string as it is entirely service dependent.

One thing cannot be disputed. This obscure issue is unknown running on Euro 5 & Euro 6 diesel.

mbdiesel12

I can agree with you on the oil aspect of this discussion. These cars should use approved oil but change oil and filter at roughly 5K intervals which is what others might tell you. That's cheap insurance for your piece of mind.

My fault with these engines is all the ancillary problems we read about here. I know blogs are biased samples but we will never know the extent of these issues because MB will never release the repair incidence on these problems. Just looking at this site we see repeated failures of timing chains stretching, turbo oil seals failing, DPF sensor problems, DPF soot problems (which I grant are probably common to other diesel engines), and AD Blue tank failures. Where there's smoke there's usually fire in my opinion.

For instance, I just got back from the dealer. I had a check engine light for an Ad Blue tank heater failure. I have only 48K on my vehicle. Add this to the list of others here that have had the same premature failure of the tank heater. I know the heater resides in a caustic environment but wouldn't you think they could redesign the system for better longevity? These aren't cheap repairs.

At least my 7/70 MB extended warranty covered it. This car will be gone before my warranty expires. Too many potential expensive repairs building up. Let's not even talk about how much a $62K car has depreciated because people don't want to buy into the MB repair costs.

Glyn M Ruck

See my long list of previous recommendations about halving the drain interval using US diesel. As I have noted previously forums concentrate issues. Some only seek out & post if they have an issue.

In torrid SA 350 Bluetec's are considered highly reliable.

mbdiesel12

I wonder if the engines for SA and the US models have differences. Maybe not.

To support my timing chain theory, I've had 4 UOA's done on my oil changes starting from 28K miles. I now have 48K miles.

The iron content results, starting from 28K miles and going forward have been 84, 68, 52, 67, 65. That seems high based on UOA's on my other vehicles. Quite high in fact. Others have seen similar results with the OM642. I can only speculate that timing chain wear may be part of the cause but I admit I'm guessing here. Maybe you have other thoughts Glyn.

Glyn M Ruck

As I comment earlier in the thread SA originally sourced ML350 Bluetecs from Tuscaloosa. They were so badly built that we moved supply to Graz. Graz production was excellent. When the Graz contract ceased we reverted to Tuscaloosa & they are now far better. This is a very fussy market. Benz vehicles built here are excellent & hold value. Our East London plant frequently beats Bremen & Sindelfingen in the quality round robin.

SA engines are higher output. They are derated for the US market. No one can tell me why. Some homologation requirement??

Your wear levels averaging maybe 65ppm are not bad for this engine. The likely source of most of it is the cam & tappet area. Some could be chain & sprockets. What are your silica levels? You should only worry when you have a sudden peak from the norm. You are lucky you don't have a Mack engine. They are excellent & do huge mileage but typically give you Fe levels of approx 350ppm on short drain.

All engines have a standard wear profile & one should compare like with like. I would be interested to see what 229.5 oils would do to the wear profile at the same drain interval.

smiledr996s

Glyn M Ruck

What samples are what here? All copper levels are insignificant. The shorter the drain interval the lower the wear elements will be.

smiledr996s

mbdiesel12

Correct. My iron levels are averaging about 65 and have come down and seem to have stabilized. All the other elements seem fine and are very stable and consistent.

My silicon levels are also very consistent at about 7 across all of my samples. I've used two different types of oil since owning the vehicle and have settled on Pentosin Super Performance III 5w30 spec 229.51.

I am a little surprised that the silicon level hasn't gone down by now but Blackstone has never commented on it's level so I assume all is well.

Glyn M Ruck

Blackstone is an excellent operation. I can see that they are not sure what to comment. Their comments are only as good as all the information provided with the used sample.
There are no alarming wear levels in any of the samples. 229.5 should give better results than .51/52 from a wear perspective. Understand when comparing elemental wear levels that 5ppm at 5K change is an identical wear level as 10ppm at a 10K interval. From additive levels I thought we had more than one formulation here.

Blackstone can't separate/differentiate silica (dust,dirt) & silicone levels. 5 to 7ppm Silicon is the air release agent in the oil (silicone antifoam additive). Your air filtration is perfect at these levels and not contributing to wear.

ot1

Glyn M Ruck

Sadly one would also get into the argument as to what a reasonable person would do. It could be reasonably argued that a person/owner would pull the dipstick & check the oil level from time to time. Doing this would immediately show that something was going awry with oil thickening long before the sump contents turned to a thick gel.

mbdiesel12

Would a sludged engine typically show up as an extremely high viscosity reading during a routine UOA or would the more liquid oil sample hide the extent of the sludging?

I'm just wondering if routine UOAs are an early indicator of problems.

Glyn M Ruck

UOA would certainly show viscosity increase. Depending on how representative the sample is there could be some thicker surface sludging/depositing but it would give you a good early warning.

mbdiesel12

Let me expand my question so I can more fully understand the value of a UOA in predicting potential engine sludging.

Let's say someone, maybe a dealer or prior owner, failed to use use the proper oil or failed to change oil over long periods of time and the engine had already developed some level of sludging.

Now a new owner without prior knowledge of the vehicle comes along and does everything correctly from an oil standpoint. They use the correct oil and change it at 5K or so intervals.

If the new owner were to do a UOA would you expect it to show elevated viscosity from the prior sludging or would it more likely reflect a more normal viscosity?

I'm just trying to determine the value of UOA testing on these vehicles. Perhaps as a tool for pre-purchase inspections. Maybe it can prevent someone from an expensive purchase or warn people of pending problems.

Glyn M Ruck

Obviously one would ideally like to start with a sample of the old oil for a base line & indication of impending doom if things remain as they are (so yes ~ oil analysis prior to purchase would be wise). However ~ with the increased detergency of fresh oil & shorter drain I would expect to see an initial rise in viscosity & insolubles etc (over new oil) as the fresh oil starts cleaning up the engine of gunk that will then slowly reduce if the new regime is maintained.

A friend has recently purchased an ML with 35K miles & we did exactly that ~ pre purchase sample which was fine. We then stuck a boroscope into the engine to take a look & everything was spotless.

dave2001auto

mbdiesel12

If you're looking for solids it's a good practice to cut open your filter and look for metal particles. Very easy to do with the stock filter since there's no metal housing.