The 164/166 + 642 guys are busy replacing oil cooler seals. No time for the forum.

I’d be interested in a guide too.

Sixto
05 E320 wagon 205K miles

 

Yeah I've heard about the oil cooler seals, that's a known problem. How bad to fix? How long does the repair last before the seals go bad again?

 

It's a gnarly fix. The coo;er is in the valley and as such the
intake manifold has to come off. At which point the updated seals
are better and last longer, but based on the 8+ hour shop time
the oil cooler should be replace also. That is the way I have
seen it done.

 

It's a gnarly fix. The coo;er is in the valley and as such the
intake manifold has to come off. At which point the updated seals
are better and last longer, but based on the 8+ hour shop time
the oil cooler should be replace also. That is the way I have
seen it done.

It's more like 13.5 - 16 hours minimum. Warranty time is more than 8 hours. I have replaced MANY oil cooler seals on 642s, never have I ever replaced the oil cooler.

 

When a job takes that long, the list of while-you’re-in-there grows. Wiring harnesses, sensors, anything plastic or motorized…

They’re smoking some funky stuff at MB when the transmission is more reliable and takes less time to replace than an oil cooler seal.

Sixto
05 E320 wagon 205K miles

 

When a job takes that long, the list of while-you’re-in-there grows. Wiring harnesses, sensors, anything plastic or motorized…

They’re smoking some funky stuff at MB when the transmission is more reliable and takes less time to replace than an oil cooler seal.

Sixto
05 E320 wagon 205K miles

To be fair, it's not so much the amount of time it takes to replace something as about the frequency of required repairs. If the oil cooler seals have been replaced then it's likely one would never care how long they took to replace. Knowing about these one can negotiate a purchase and adjust price accordingly: MUST have/show receipts! If you don't know, then, well, it'll be another episode in the school of hard knocks.

 

Few samples of sudden unexpected seizure.

https://www.benzworld.org/threads/2011-gwagon-350.3123688/#post-18625826

https://www.benzworld.org/threads/bluetec-engine-seized.2910226/#post-16795090

https://www.benzworld.org/threads/x.3048615/#nested_reply_top_post

 

The common theme in the first two is engines that were mal-treated. First video is an engine in which the oil was sludge, mechanic speculates that the oil wasn't changed ever. Second case, maybe sludge in engine from a life of short trips. Third case is not clear what caused the engine seizure.

My take away: sludge kills! I'll check for sludge in this GL I'm looking at.

I also learned about heat tabs, which melt if the engine is over heated. I'll need to learn more about where those are and check those too..

 

Lets see...

Def pump
Def injector
Differential pressure sensor
Backpressure sensor
Swirl flaps
EGR valve
EGR cooler
Oil cooler
Oil cooler seals
Timing chain
Timing chain tensioner
Turbo
Turbo actuator
Black death

Is it any wonder why the 642 guys aren't on forums?

Take a good look at the AEM warranty extension, see what they cover. That list is pretty exhaustive and an indication that all of those parts fail often.

There's a reason why 648 equipped cars cost more than later 642 cars.

 

Thanks!

What does "AEM" stand for, and is that warranty extension available online? Terms?

 

Are om642 turbos and actuators more fragile than on om648s?

EGR and swirl flap issues also exist with om648s (to a lesser extent?), not to mention just about every diesel engine that came with them: I believe that BMW ultimately saw the light on the swirl flaps and stopped using them. The DEF stuff for sure is an issue, though such issues are also fairly common across the diesel engine industry. Was not aware of timing chain issues (again, I am not a close follower of these engines), but if a weak spot then that definitely isn't good.

 

It's the center mounted turbo that's causing all the issues. Turbo is not cooled unlike later cars, so extended oil change interval = play in turbo shaft or clogged turbo feed lines.

Dont know if BMW stopped using swirl flap, from what I see here they still use swirl flaps all the way to N47 and N57 engines. B47 and B57 engines don't exist here in the US, so if they removed the swirl flap on those, great, but we don't get those engines.

Timing chain issues and turbo issues go hand in hand with extended oil change intervals.

Ambulance sprinters with om642 have coolant lines for turbo and multiple aux coolant pumps and a significantly shortened OCI -- something like a OCI per 200 hours (same as 5000 miles OCI) and they have significantly less issues with coking or sludge with both timing chain and turbos. This is even with all the idling those sprinters see.

Take what you will from that.

 

Apparently what I'd read on the swirl flaps is incorrect: I thought it was a fairly reputable article, sigh. Seems that BMW still had them with those later engines. While looking it up I ran across this article and thought it a fairly reasonable representation of most newer diesel engines:

https://lifeonfour.co/buyers-guides/bmw-b47-diesel-engine-reliability/

I don't necessarily concur that turbos' lifespans are about 150k miles. I can understand more fragility due to the center-mount. All my engines are in-line and all are turbo [diesel, of course] and oil cooled with roughly 175k miles to 250k miles all on original turbos: and all have moderate performance increases, higher-than-stock boost.

 

How you drive and how you treat the car also affects turbo longevity. Multiple short trips that doesnt allow the engine oil to fully warm up is a problem. After a freeway drive or extended full throttle runs with boost, engine needs to run for a few minutes to cool down the turbo and prevent heatsoak. So getting off the freeway and taking about 10 minutes of street at low speed is enough to cool down the turbos, those are generally fine. But if your home is literally next to the freeway and you shut off right after freeway speeds? That's a receipt for problems.

Commute time needs to be about 30 mins or higher. Less than that, problems.

Diesel does not make sense for a vast majority of people, since the gas mileage savings is offset by increased cost of repair when things break from short commutes.

 

You forgot brittle exhaust manifold inner layer, which usually is destroying turbo. Oh I wish someone would start making welded manifolds in series...

AFAIK is usually turbo actuator which fails (not saying cooling issues wouldn't be a problem), however oil quality and age is really important like Deplore says. In my opinion its not parts fault is stupid people heavily misuse and treat it badly. Everything can be broken, if wanted.

Swirl flap failure is usually actuator motor, which is caused by turbo ^^^^ oil leak.

DEF/nox problems are not engine related, all cars which are fitted with that planet saver, are saving dealers profit only.

I remember lately reading one 'new' oil cooler seal failure.

Black death is something I can't understand, why MB has not changed injector fastening system. It has now been on field nearly 25 years... so its problem of ALL MB diesel engines too.

Timing chain is pretty weird, I can't remember reading any fatal OM642 engine failures caused by overstretched chain or broken tensioner (like some M271 or OM651 engines), even there has been several pictures which proves that timing can be off several degrees, and tensioner parts have been fallen on floor when tensioner pulled out.

 

DON'T BUY ONE

 

If you are a glutton for punishment and want to spend more
cents per mile than you ever have on any car you have
owned as a daily driver then please get this one.

I urge you not to get this vehicle no matter how
attractive it seems early in the game.

 

Can we talk about X166 Airmatic next?

Sixto
05 E320 wagon 205K miles

 

Can we talk about X166 Airmatic next?

First let me turn down the volume. I don't want my eardrums to burst

 

Ironically enough, the airmatic portion is the most reliable part in a x166. As in, it's reliable in the sense that it will consistently fail at 90-110k miles. Almost always the fronts.

As for everything else.....whelp. I'd say that the seats are reliable? Ohh, the window regulator! And the door lock actuators never break! Those are good.

...yeah.

 

Hi Max. I've got a 2011 e350 bluetec with the om642. I purchased back in 2014 when that car had come off lease. There was only one previous owner, and it was maintained by the dealership in Columbus, GA, and they shared the cars history with me. At 53,700 miles, I had the dreaded oil leak caused by the cheap ass O ring they employed. They also replaced my oil cooler at that time as it had slightly warped due to overheating (so they said). After arguing with benz (was well out of warranty) they paid for half the repair. I change oil with mobile 1 esp 0w30 every 5k miles, and pretty much keep up with other maint items ... fuel and air filters, transmission fluid change and such. That said I have 114000 miles now. Still running strong: slight oil leak at moment coming from sensor going into top of oil reservoir. Still get about 35 mpg (700 miles on one tank) on the highway and 500 miles in the city. ... same as when I purchased it. So. I'd say gather as much info as you can get on the vehicle, be weary if they were doing 10k oil changes vs 5k. And of course be sure the oil seal has been changed

 

Thank you Charles, it's nice to hear from someone that actually owns a vehicle with this engine.

I'd love to hear more from others that also have experience.

How long do the injectors last? Glow plugs?

 

Well a W212 is not the same chassis, but the diesel was and will
be plagued with the same issues. Anybody that thinks they are saving
money with any MB that has that terrible engine should check there
cents per mile with cost of diesel and the never ending repairs.

 

I have owned 2 cars with OM642 now 4 and 6 years. I have changed timing chain and tensioner as a preventive maintenance right after I bought both cars. What else engine related parts has been changed/repaired addition of normal service items; two boost hoses, exhaust temp sensor, turbo seal, crankcase breather valve to both engines, serpentine belt.

Not a single injector/seal (unlike my previous OM612, OM613 and OM648).

I agree adblue system is money pit. That's why it was one 'must not have' feature when I was looking my W212.

 

There's injector seals (as are issues on om648s- catch them early enough and they're easy enough to deal with; inexpensive)* and then there are the injectors. Doesn't matter what common rail engine, CR injectors lifespan is really only good up to around 150k miles. Will they last longer? Yes but injectors are extremely important. One starts to face leaking injectors and that leads to several issues: poor fuel economy, rough running, increasing potential for engine damage etc.). ALL is plus-or-minus. Poorly maintained engines and or poor fuel will shorten the life of injectors.

* Lots of cases where there's been zero seal issues with upwards of 200k miles. While this design is on the poor side it's not really catastrophic IF one knows to keep a watch out (or just spends a few bucks and replaces seals preemptively).

I don't know about others but I look to get my used vehicles in as near-to 100% as possible so that I can then expect to see 100k miles of low repair costs (and longer intervals between being sidelined with costly repairs). Yes, hard to know exactly how long something is going to hold up. Those things that can be addressed with relatively minor ease are good to be addressed up-front and that will leave fewer things to cause concern.

In the light-duty truck world I know that 6.0L Powerstrokes are very problematic. BUT, people claim that with some aftermarket fixes they're good engines. My preference has and is likely to always be, in-line engines [diesel].

So, Max, if you add up the costs to take care of the various [possible] issues and make sure you have money set aside AND if you really like the vehicle (it provides the functionality that you are seeking- focus on NEED, fancy/blingy/cool things aren't a NEED unless you're into art) then get it. If one knows up-front what one is getting into and is OK with that then all is good. I'd challenge most here to justify any of their vehicles- unless one uses a vehicle to make money it's but a convenience.

Used vehicles are always a risk. Trick is to come up with reasonable mitigations (and if not then stay away). This is MB. One wouldn't walk into a MB dealership and ask whether one can afford a vehicle. I don't think it's any different with used: lower up-front cost but there will always be a significant amount of cost over time (unless a person does what I do and shell out lots of money up-front).

 

I guess I'm an odd duck. I could afford to buy a much newer vehicle, but I enjoy learning and fixing my own cars. The cost of quality parts doesn't bother me. I really hate to pay someone else to work on my cars, but I do know my limits, and I can afford to pay a mechanic when I need to.

Completely agree and understand that all used cars carry risk, and if elimination of risk was the goal, the cost will be a high purchase price, high insurance, high taxes. In my mind, a used car that I can maintain and repair will always be a better value than a new car.

Thanks Dieselbound and Mersum1es for your inputs.

 

Max, quack, quack! I'm of the same mind (one just needs to look at the restoration work on my car) I've never bought a new car and never will. I go after the things that fit my requirements list; and, am willing to go the extra mile to make it happen (no one would have advised me to get my car from the Chicago area, yet that's what I did- I came up with the correct risk mitigation plan)

 

I sense it’s Diesel or nothing for ducks like you

Sixto
05 E320 wagon 205K miles

 

Although diesel is preferred, gassers have their place. I've got four gassers at the moment, and just two diesels, but if I could get to just two of each I'd be happy.

 

I still get to sniff gasoline when I run my chainsaws (and if there were diesel-powered chainsaws...) I am, though, envious that you have a wagon: someone here in the States fitted an om648 into a wagon- talk about a LOT of work! impressed by such work.

 

Summarizing what I've learned so far about the OM642:

Oil cooler seals are a major weakness and a royal pain to replace, but the seals seem to be updated and once replaced they last longer than the originals. Check to see if this work is done.

Mercedes has an Approved Emissions Modification campaign for this engine series, check to make sure it has been done.

These engines, like most modern engines, are subject to oil sludge build-up that will destroy the engines. A life of short trips and extended oil drain intervals will contribute to this problem. How to detect this issue? Lab analysis of an oil sample? Drain the engine oil and measure the volume, compare to factory specified oil capacity?

Injectors will last about 100k to 150k miles, and should be changed immediately when their performance degrades. The injector seals will leak and the Black Death (similar to the OM648) is a problem, but this appears to be less frequent than what the OM648 suffers.

Soot build-up in the intake manifold from a leaking EGR valve can be a problem.

Various turbo problems are an issue.

 

Or do....I love those cars. Money makers. Just the NOx, DEF system alone is free money.

Did a sprinter with broken def pump, leaky def line and damaged def injector + 1 NOx sensor... $2400. Took me all of 4 hours, and most of that was archeology chiseling.

Very relaxing, if you can believe it.

 

Would a 2009 model GL have the DEF system?