Really good video of an OM642 teardown (ML350)
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From: V E G A S
1922 Ford Model T / no OBD
The engine was/IS (?) produced for about 20 years and with higher than usual for MB maintenance requirements proved to be real workhorse, reaching 1/2 million miles in Sprinters just fine.
The video shows the phenomena highlighted in very long topic in this section, where inadequate oils create gelatin.
Even my older OM642 allows for older classification oils, I don't put anything below 229.52 oils in it.
Passed 200k miles this summer in almost 5 tons Sprinter, still working like Swiss watch.
When I love the I4 diesel better for fuel economy, the V6 is still excellent choice for those who's priority is higher torque.
The video shows the phenomena highlighted in very long topic in this section, where inadequate oils create gelatin.
Even my older OM642 allows for older classification oils, I don't put anything below 229.52 oils in it.
Passed 200k miles this summer in almost 5 tons Sprinter, still working like Swiss watch.
When I love the I4 diesel better for fuel economy, the V6 is still excellent choice for those who's priority is higher torque.
Last edited by kajtek1; Aug 21, 2022 at 12:21 PM.
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From: Where the Army sends me.
GL 350 Bluetec
I would agree with you that the N/A V8 motors were solid performers with a long lifespan.
But… for somebody shopping for vehicles post 2012 the options for a motor with solid lifespan are a bit bleak. M278s have the cylinder wall scoring issues which inevitably lead to a failed motor. M274s have a pretty bad track record for sudden catastrophic failure due to piston cracking. You don’t have to look past the first page under a category to find a lot of threads. M276 seems pretty solid but they aren’t that numerous.
The OM642 might not be so bad of an option for certain models and time frames. I’m not having a lot of luck convincing my wife that a 2011 E550 is actually a better choice than a 2014.
But… for somebody shopping for vehicles post 2012 the options for a motor with solid lifespan are a bit bleak. M278s have the cylinder wall scoring issues which inevitably lead to a failed motor. M274s have a pretty bad track record for sudden catastrophic failure due to piston cracking. You don’t have to look past the first page under a category to find a lot of threads. M276 seems pretty solid but they aren’t that numerous.
The OM642 might not be so bad of an option for certain models and time frames. I’m not having a lot of luck convincing my wife that a 2011 E550 is actually a better choice than a 2014.
Last edited by Panzerknacker; Aug 21, 2022 at 03:26 PM.
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This place is a joke.
I would agree with you that the N/A V8 motors were solid performers with a long lifespan.
But… for somebody shopping for vehicles post 2012 the options for a motor with solid lifespan are a bit bleak. M278s have the cylinder wall scoring issues which inevitably lead to a failed motor. M274s have a pretty bad track record for sudden catastrophic failure due to piston cracking. You don’t have to look past the first page under a category to find a lot of threads.
The OM642 might not be so bad of an option for certain models and time frames. I’m not having a lot of luck convincing my wife that a 2011 E550 is actually a better choice than a 2014.
But… for somebody shopping for vehicles post 2012 the options for a motor with solid lifespan are a bit bleak. M278s have the cylinder wall scoring issues which inevitably lead to a failed motor. M274s have a pretty bad track record for sudden catastrophic failure due to piston cracking. You don’t have to look past the first page under a category to find a lot of threads.
The OM642 might not be so bad of an option for certain models and time frames. I’m not having a lot of luck convincing my wife that a 2011 E550 is actually a better choice than a 2014.
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Senior Member
Joined: Apr 2009
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From: Where the Army sends me.
GL 350 Bluetec
I agree with you, I was comparing the 272/273 with the om642 as they are from the same era, at least here in the U.S. Right now it seems the m276 was the last reliable engine I would want to own, although now they are ageing and starting to show problems with camshafts and camshaft adjusters, however it's not widespread as of yet. The m278 seems good for only around 100k miles. The later m274's after 2017 or so seem ok, but the newest version m2?? are having cylinder head/valve issues.
We just bought a 2015 GL350 bluetec and I am glad we didn’t end up with a M278. At the time I didn’t realize the later versions of the GL had a M276 motor, which may have affected my decision some but I still don’t regret it. I’ll be changing my oil every 5000 miles. Mobil 1 ESP is 229.52 compliant and reasonable cost at Auto Zone.
Last edited by Panzerknacker; Aug 21, 2022 at 05:10 PM.
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From: V E G A S
1922 Ford Model T / no OBD
I simply do oil test.
OM642 has 10k miles intervals in car engines, when it does have 20k miles intervals oil change in Sprinters, where the same engines do have much bigger oil pan.
I just did oil change after 16k on my Sprinter due to about 3 years since PO did it and the lab tells me I should go longer.
Don't have the copy on this computer, but I might to attach it later.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
I wonder how many of the OM642 motors met an early demise at the hands of the manufacturers recommended 10k mile oil change interval.
We just bought a 2015 GL350 bluetec and I am glad we didn’t end up with a M278. At the time I didn’t realize the later versions of the GL had a M276 motor, which may have affected my decision some but I still don’t regret it. I’ll be changing my oil every 5000 miles. Mobil 1 ESP is 229.52 compliant and reasonable cost at Auto Zone.
We just bought a 2015 GL350 bluetec and I am glad we didn’t end up with a M278. At the time I didn’t realize the later versions of the GL had a M276 motor, which may have affected my decision some but I still don’t regret it. I’ll be changing my oil every 5000 miles. Mobil 1 ESP is 229.52 compliant and reasonable cost at Auto Zone.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
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From: V E G A S
1922 Ford Model T / no OBD
If you can't do research and can't monitor your engines, you better stick with cheap gas engines.
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From: Orbiting the planet
This place is a joke.
Well said. The last OM642 I saw that sludged and seized was because the owner thought he knew better than MB and was running Royal Purple oil...
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
So - the owner kills the engine by running an unapproved (and at that a badly formulated oil that has a well-documented history of destroying various engines), but it's the OM642 that is junk, not the owner's poor or inadequate maintenance or operation? Yeah, really solid logic there.
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From: Orbiting the planet
This place is a joke.
So - the owner kills the engine by running an unapproved (and at that a badly formulated oil that has a well-documented history of destroying various engines), but it's the OM642 that is junk, not the owner's poor or inadequate maintenance or operation? Yeah, really solid logic there.
Last edited by E55Greasemonkey; Aug 27, 2022 at 12:14 PM.
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Yes, it's still a junk engine. Thousands of other ones have seized, broken down, gone into limp mode, required thousands of dollars of repairs, or leaked out most of the factory recommend oil. Definitely the worst engine MB has built in the modern era. With the exception of the early balance shaft issues, gasoline m272/273 engines are running an easy 250k miles without every being opened up.... with every kind of oil being used in them. Again, there is absolutely no reason to own the om642 over the m272/3 in any of the models where you had a choice. 211,212,221,164 etc.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
The wife kind of rolls her eyes at me when I tell her we can't use the ML for short trips, but she sort of understands why. That's what our gassers are for.
Gas engines can't yield upwards of 30mpg and still give you 455 ft. lbs. of torque on demand... Just say'n.
Gas engines can't yield upwards of 30mpg and still give you 455 ft. lbs. of torque on demand... Just say'n.
Last edited by rapidoxidation; Aug 27, 2022 at 08:19 PM.
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W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Get the Viton oil cooler seals and you won't have more issues (if you do the job right). Besides, it's just a seal that gets leaky over time - which does not lead to a catastrophic engine failure by any means, unlike, say, timing chain or balance shaft issues on your much loved M272 or M273. Those do result in catastrophic engine failures... leaky oil cooler seals on the early OM642s do not.
Why do you insist on continuing to beat the same dead horse?
Why do you insist on continuing to beat the same dead horse?
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From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
I agree it's a turd as is, only from my own experience.
The internal oil cooler. Seals leak. MB changed over to the purple Viton seals. These updated seals do a better job, but can't handle the heat so they end up leaking again. It'd be cool if it was possible to bypass the cooler and mount one externally.
Dactivate the swirl valves to avoid gunking/carbonizing up the internals
Deactivate DPF
Replace oil (with anything but the specified 229.51, 'cause according to MB, that oil is now officially the scourge of the planet) every 10k kms
According to some, there are no issues with the OM642 as is. Mostly in our heads. Okey dokey.....
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From: V E G A S
1922 Ford Model T / no OBD
Nah, it's all in your head LOL
I agree it's a turd as is, only from my own experience.
The internal oil cooler. Seals leak. MB changed over to the purple Viton seals. These updated seals do a better job, but can't handle the heat so they end up leaking again. It'd be cool if it was possible to bypass the cooler and mount one externally.
..
I agree it's a turd as is, only from my own experience.
The internal oil cooler. Seals leak. MB changed over to the purple Viton seals. These updated seals do a better job, but can't handle the heat so they end up leaking again. It'd be cool if it was possible to bypass the cooler and mount one externally.
..
How many takers would be for such kit for Mercedes?
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Joined: Jun 2022
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From: WA State, USA
2014 Cummins, 2014 E250 Bluetec
On that engine the egr cooler was also right by the oil cooler which got the delete treatment. Was a fun engine once the querks were worked out,if ya liked a hot rodded v8 diesel that is. Ofcourse 350hp from a engine originally designed for about 150hp i think was always living on the edge.
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Nah, it's all in your head LOL
I agree it's a turd as is, only from my own experience.
The internal oil cooler. Seals leak. MB changed over to the purple Viton seals. These updated seals do a better job, but can't handle the heat so they end up leaking again. It'd be cool if it was possible to bypass the cooler and mount one externally.
Dactivate the swirl valves to avoid gunking/carbonizing up the internals
Deactivate DPF
Replace oil (with anything but the specified 229.51, 'cause according to MB, that oil is now officially the scourge of the planet) every 10k kms
According to some, there are no issues with the OM642 as is. Mostly in our heads. Okey dokey.....
I agree it's a turd as is, only from my own experience.
The internal oil cooler. Seals leak. MB changed over to the purple Viton seals. These updated seals do a better job, but can't handle the heat so they end up leaking again. It'd be cool if it was possible to bypass the cooler and mount one externally.
Dactivate the swirl valves to avoid gunking/carbonizing up the internals
Deactivate DPF
Replace oil (with anything but the specified 229.51, 'cause according to MB, that oil is now officially the scourge of the planet) every 10k kms
According to some, there are no issues with the OM642 as is. Mostly in our heads. Okey dokey.....
If you decide to do the job right and replace all 28 gaskets and seals with OEM parts, the kit is about $150. The oil cooler Viton seals themselves are about $5.
If you are getting near the 240,000 km mark and/or also want to proactively replace the PCV valve, swirl flap actuator (motor), additional gaskets, various tubes, hoses, brackets, bolts and everything else that may be getting there mileage-wise, the parts tally is about $600.
It's a full weekend job but nothing that requires anything other than a copy of WIS, a socket set and a basic tool kit. If you're paying someone to do it, it is probably 16 hours or so.
