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So to start off with I have scene/read/commented in several oil related discussions/arguments/debates on this matter. My thread is more about why have om651 not had the jelling issues related to the om642?
Concensus is OM642 in US with biodiesel percentage and running 229.51 oils caused engine to block up with tar. However that being the case OM651 like mine running 229.51 oils its whole life because thats what the dealers had in barrels does not seem to have that same issue running the same diesel fuels.
To be clear both engines had various specs for oil (228, 229.whatever) and then the later and or specific engine code 642s require only 229.52 oils.
Not meant to be a oil discussion thread per say but more of is there some reason only the one engine is effected? Never scene/heard about this in any other diesel engine sold in the US unless they ran the oil to beyond end of life and kept going for a much longer time.
So to start off with I have scene/read/commented in several oil related discussions/arguments/debates on this matter. My thread is more about why have om651 not had the jelling issues related to the om642?
Concensus is OM642 in US with biodiesel percentage and running 229.51 oils caused engine to block up with tar. However that being the case OM651 like mine running 229.51 oils its whole life because thats what the dealers had in barrels does not seem to have that same issue running the same diesel fuels.
To be clear both engines had various specs for oil (228, 229.whatever) and then the later and or specific engine code 642s require only 229.52 oils.
Not meant to be a oil discussion thread per say but more of is there some reason only the one engine is effected? Never scene/heard about this in any other diesel engine sold in the US unless they ran the oil to beyond end of life and kept going for a much longer time.
Who says that only the OM642 but not the OM651 could be affected by the oil gelling if you use fuel with a nigher biodiesel content combined with inadequate oil or inadequate OCIs?
"Concensus is OM642 in US with biodiesel percentage and running 229.51 oils caused engine to block up with tar. However that being the case OM651 like mine running 229.51 oils its whole life because thats what the dealers had in barrels does not seem to have that same issue running the same diesel fuels."
When I knew I was getting a new DPF under the AEM I started using the cheaper 229.51 in my OM-642, and the oil still seems like runny pudding by 6.200 miles, which is my OCI.
"Concensus is OM642 in US with biodiesel percentage and running 229.51 oils caused engine to block up with tar. However that being the case OM651 like mine running 229.51 oils its whole life because thats what the dealers had in barrels does not seem to have that same issue running the same diesel fuels."
When I knew I was getting a new DPF under the AEM I started using the cheaper 229.51 in my OM-642, and the oil still seems like runny pudding by 6.200 miles, which is my OCI.
I'm not sure the oil is the problem in this case. Granted putting 229.51 gasoline oil in a diesel is daft but I think the jelling has more to do with the way the 642 regenerates the DPF. Would be interesting to see the soot and fuel content of the oil once it turns to jello.
I'm not sure the oil is the problem in this case. Granted putting 229.51 gasoline oil in a diesel is daft but I think the jelling has more to do with the way the 642 regenerates the DPF. Would be interesting to see the soot and fuel content of the oil once it turns to jello.
MB 229.51 is (or was) a specifically formulated oil for DIESEL engines, not gasoline, and you are again completely wrong about what causes the gelling. Just because you believe the earth is flat it does make it so.
Any why do you all keep asking the same question over an over again in various threads when the same has already been answered twenty seven times? The answers won't change just because they don't fit your preconceived notions and you don't like hearing that they are wrong. There's a quote attributed to Einstein that “Insanity is doing the same thing over and over and expecting different results” - which is exactly what you are doing. Stop wasting everyone's time.
MB 229.51 is (or was) a specifically formulated oil for DIESEL engines, not gasoline, and you are again completely wrong about what causes the gelling. Just because you believe the earth is flat it does make it so.
Somebody forgot to tell Mercedes Benz. Look at all those gasoline engines they listed under 229 51. You better call them up and tell them about their mistake before its too late!
😂
Just because a HDEO oil is approved for use in a gasoline engine as well as a diesel one, it does not mean that they made a mistake. The only mistake here is you making an assumption that you can't use a 229.51 oil in those engines for which it is approved. If I need to call anyone, it is your parents and teachers who made the mistake of not telling you that comprehension and logic are not your strong suits.
Now, can you please stop pissing in the wind and complaining that you're getting sprayed? Pretty please?
Who says that only the OM642 but not the OM651 could be affected by the oil gelling if you use fuel with a nigher biodiesel content combined with inadequate oil or inadequate OCIs?
Thanks I have just never heard nor scene anything online to say om651 had the same issue. They are here in the US running the same fuel which can be all over the place in regards to biodiesel contect regardless of what the sticker says on the pump. Anyhow Ill refrain from inquiring about this subject any further.
If you are looking for a succinct article on the subject, have a look at https://biodieselmagazine.com/articl...fuel-dilution/. And, if you Google "Fuel dilution by biodiesel", you'll get lots of relevant hits (the article I linked above is the second or third that comes up) that explain why biodiesel causes oils to oxidize and polymerize (i.e. gel) as well as cause piston rings to stick. There are a number of papers and scientific studies that explain the mechanism of action and the exact issue that tits1 here (pun intended) is having with stuck piston rings but which he unfortunately doesn't want to accept. You can lead a horse to water but you can't make it drink.
Thanks I have just never heard nor scene anything online to say om651 had the same issue. They are here in the US running the same fuel which can be all over the place in regards to biodiesel contect regardless of what the sticker says on the pump. Anyhow Ill refrain from inquiring about this subject any further.
Don't let that idiot stop you from asking. It's a good question. I don't think anyone has the right answer yet. And you're right, the 651 doesn't suffer the same oil failure mode and as the 642. I'm not sure oil or fuel is at fault here.
Originally Posted by Diabolis
Just because a HDEO oil is approved for use in a gasoline engine as well as a diesel one, it does not mean that they made a mistake.
229.51 oils are not HDEO. Show me one oil manufacturer putting the words "heavy duty" or "HDEO" on a 229.51 gasoline engine oil. 😆
Don't let that idiot stop you from asking. It's a good question. I don't think anyone has the right answer yet. And you're right, the 651 doesn't suffer the same oil failure mode and as the 642. I'm not sure oil or fuel is at fault here.
229.51 oils are not HDEO. Show me one oil manufacturer putting the words "heavy duty" or "HDEO" on a 229.51 gasoline engine oil. 😆
Go ahead I'll wait.
People not only have the right answer, they even have the right solution... you just don't want to accept it because it does not fit with your bias and preconceived notions.
Show me one piece of ID of yours that says "Idiot"... or for that matter, show me one that says "Human". Go ahead and I'll wait.
Not exactly what I intended. Was more curious if there was something different say in cylinder ring construction, maybe cylinder lining material, sump size, oil temperature difference while under load ......
or maybe its just because the US has crappy biodiesel and there are much fewer om651 engines over here.
When I follow the subject pretty carefully, I remember only 1 of the incident with frozen engine where owner admit he put wrong oil in it.
All other had service done by dealers, or other shop, who never admitted what oil they put in those engines.
Meaning that since OM642 engines are much older than OM651, it is quite possible that in older days they got badly outdated oils, when 4-bangers diesels are such new technology on US market, that mechanics put more attention to using oils per specifications?
Than having E class and Sprinters with both engines, the OM642 show steadily 20-30% higher fuel consumption, while doing precisely the same jobs.
So is it possible that the extra burn fuel creates some strange chemistry, that affects the oil this way?
I am in no position to confirm any of those theories and sounds like MB USA would be the last interested in doing so.
Than having E class and Sprinters with both engines, the OM642 show steadily 20-30% higher fuel consumption, while doing precisely the same jobs.
So is it possible that the extra burn fuel creates some strange chemistry, that affects the oil this way?
I am in no position to confirm any of those theories and sounds like MB USA would be the last interested in doing so.
This is why I suspect it has something to do with the way the 642 regens the DPF and the oil might not be at fault. A lot of that extra fuel is fired off during regeneration. Some of the regen fuel is getting past the rings and into the oil along with soot and all the other byproducts of combustion. Whatever lessons were learned from the 642 (their first engine with a DPF) we're baked into the 651.
From personal experience with the 642 fuel economy improves about 20% when DPF regeneration is turned off.
I had oil test done on OM642 after 14,500 miles (in Sprinter with 20k intervals) and it shows less than 0.5 % of fuel, so theory about regeneration diluting the oil with fuel goes down the drain.
My Sprinter with ove 200k miles does DPF regeneration every 120 miles, so about 3 regenerations on single tank of fuel.
I had DPF delete on my E250 BT and reversed the delete for AEM. No noticeable difference in fuel consumption either way.
I had oil test done on OM642 after 14,500 miles (in Sprinter with 20k intervals) and it shows less than 0.5 % of fuel, so theory about regeneration diluting the oil with fuel goes down the drain.
What model year? How does it compare to earlier engines? Pre AEM or postm How many changes has MB done this engine over the years. The oil jelling is far more prevalent in the earliest 642s. You can't use such a wide brush on this. N of 1 is hardly convincing of anything.
You can't figure out what you are talking about.
Once you are saying that higher fuel consumption on OM642 create oil dillution, than you changed your theory that the newer OM642 don't dillute the oil, even they still use more fuel.
If I remember correctly, it were SCR equipped engines who froze. Meaning the latest generation.
I have no idea why some engines have an oil gelling problem, but I once owned a late '90s Toyota v6 gasser. Before I heard anything about its problem, I received a letter from Toyota saying that they had discovered that my engine type had an oil gelling problem and that they were extending the engine warranty by what I remember as quite a few years. I remember wondering why they did not give advice as to how to avoid the problem. With this in my background it is interesting to contrast Toyota's approach to that of Mercedes' on the 642.
MB 228.51 spec oil is approved for my 2014 GLK250. Chevron Delo 400 XLE SAE 10W-30 and 15W-40 ($20.62/gallon at Wal*Mart) oils both meet MB 228.51 and also API CK-4. Maybe one of them would be a good choice.
(They also met API SN, which makes them suitable for Gasoline powered engines as well.)
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