I hear you and you're not alone. MB should be ashamed of putting the OM642 engines on the road. They're a mechanical black hole of problems. Just take a quick read through this blog. None of the fixes are cheap on these engine it seems. Everything from oil cooler seal failures, engine sludging, timing chain failures, DEF heater failures, DPF sensor failures, etc., etc. Let's not even speculate about the questions surrounding emissions that are being looked at.

I have a 7/70 extended warranty on mine and just before it expires the car will be gone. Except for an early rear main seal problem and DEF tank heater CPU update the car has been reasonable so far. That's if you don't mind paying the MB dealer prices for routine services....

 

I don't know an engine who would not require some cleaning and parts when reaching 150-200k miles.
642 is very desirable engine, unfortunately the items listed above will need to be addressed before reaching 1/2 million miles. Maybe with exception of turbo, where I think OP got hosed off.
Still better than balance shafts on early 350 gasoline, or gummed valves on DI gas engines before they reach 100k.
But all those things are pretty well known, so before buying 10 years old car that is due for $10,000 maintenance jobs, I would consider buying newer model.
I am fascinated with 4-banger for comparison >>> oil cooler sits on front frame, so it is like 20 minutes to replace.
I4 engine makes everything easily accessible. .
But anyway, if you want to dump the car, I'll be happy to drive to Lexington and take it off your hands.

 

The only reason I can think of that would make the bluetec OM642 more desirable (at first) when compared with the gasoline counterparts, is that they are cheaper... until you start having this mountain of issues that people always discover during owning one of these things. I would take an OM648 any day, but I would never let a family member or friend own anything with the OM642. And yes I would still rather have a M272/M273 over the OM642... balance shaft or not, the engine gets decent fuel economy and aside from a few small oil leaks and the balance shaft on the earlier models, when was the last time you saw a M272/273 with a stretched timing chain at 30k miles.. or where you had to go out of your way to find the correct fuel station to avoid any biodiesel junk?

 

Unfortunately the failures of the parts I mentioned seem to happen well before you would reasonably expect to invest that kind of money in repairs.Take a look at oil cooler seals and timing chains for instance. Many of the failures haven't even made the 100K mark. Many are in the 50K to 100K range. Who expects that from MB? We bought these cars and paid a dear price for the diesel engine expecting the legendary longevity of the old diesel engines. Chalk it up to emission controls, poor design, or whatever but we didn't get what we were expecting. This will be my last MB also. It's no fun having a car that you're pretty well guaranteed of spending a small fortune in repair costs on. That prospect is always hanging over our heads.

I had the same thoughts with my 2006 Porsche and the design flaw in the intermediate shaft bearing failures. I had a 2006 and when that bearing fails it's a $20K engine teardown and rebuild.

Nobody makes a perfect engine but you need to look at the severity of the problems and potential repair costs.

 

That is why used MB is hardly recommended for people who take it to mechanics.
I look at oil cooler as $100 job.
Just rebuild turbo (even it really didn't need it, but I had it out) >> $45 for Garret rebuild kit.
Flaps? Had manifold out, so spend 1 hr scraping the carbon off them. No dollar cost.
Should be good for another 10 years.

 

I'm totally in with Kajetek on this. It does take a little time but if you're mechanically inclined, the satisfaction you get from fixing a job at a fraction of dealer/indy is so worth it.
the torque om642 provides, I'm not sure when I'll be switching back to a gas motor. Remember, every thing brakes in this matrix. It's ALL ***** IMHO.

 

I agree with the OP, cut your losses and move on. IMO the OM642 makes a great boat anchor.

 

Nothing like someone who doesn't own the motor commenting on it and putting it down to help make themselves feel better about owning a W211 CDI LOL. CDI is a good motor, no question, but they have their own fair share of issues none drivetrain related but the MPGs arent even close.The OM642 motor is phenomenal 455lbs of TQ under 2000 RPM helps my 5,000lbs AWD Sedan average more than 26mpg in the city, they need regular service and things break, lots of engineering goes into Benz cars. They have the fastest/hottest glowplugs in the business and my cars starts almost as fast as gas cars in 25 degree weather. To the individual discussing sludge, I am willing to bet money its due to a combo of improper Fuel with more than 5% BIO and late oil changes (multiple owners with poorly documented fuel history who probably lived in Illinois), but people wont fall on their swords when things go wrong. People have a sense of entitlement that they are owed something and they could never do anything wrong. While a fair amount of owners don't pay attention to what Diesel they are putting in their car and go with the cheaper option because they bought used and nobody explained to them they CANT use BIO DIESEL

You can pick up a used OM642 Bluetec motor (80,000 Miles) for less than $5K complete not sure what all the complaining is about! The Oil Cooler leaking is a common issue true but is easily fixable by anyone technically inclined, numerous youtube videos showing how to do it. As for the Turbo, i would have had it rebuilt no point putting new parts on used cars with over 50,000 miles, ebay is your friend.

A used Mercedes of any kind over 70,000 miles isn't for someone who wants to send the car to the mechanic for everything, thats why you can pick up a 6 yr old example for less than 30% of new retail. Anyway, please keep complaining as it helps me continue to buy great cars that are a 1st class ride, interior, safety and mechanical engineering excellence and out perform a Prius in efficiency. My cost per mile (Factoring depreciation) is less than any Hybrid Toyota, Honda, Audi, BMW and 100 times more comfortable

 

You're assuming I do not own one, I wouldn't be so harsh towards it if I didn't have first hand experience with one.

 

Not that easy.
I just went via the hassle when my 624 sucked water a year ago. I searched all over the World and the only US supplier, who advertised rebuild short block on ebay for $5000 would not answer my emails.
So 6 months search found me $3000 short block in UK and good seller charged me only $250 shipping (some US sellers want $400 for domestic shipping).
I semi-retired last year, so having "cheap labor" took the project, but seeing how complex the engine is, that would be the last thing I would advise for DIY.
Agree with other points in your reply
But I am car enthusiast. Have a friend who does black top racing. He pulls his Chevy engine out and do some kind of rebuild every month.
All for fun as there is no money in this.

 

Howdy guys this is my first post here looking to purchase a used MB diesel. Either an ML or GL. My last oil burner was a 300SDL, really liked that car, and I know that modern diesel has issues but would like some feedback on the pros and cons of the engine is the ML or GL.I know that regular maintenance is the key to longevity and plan on keeping it for a while.

TIA

 

 

So you can listen to the Guy with the W211 E that was bought for $7,500, which sold new for $60k and when the cost to maintain it with a dealer or mechanic aligns with the $60k price point they are disappointed. I would take a different approach personally. Are you mechanically inclined? If so dont be afraid of miles on the car, try to get the newest car you can afford, and run a VMI on it, it will tell you if the car was a problem child before your ownership and also how it was maintained.

After 2012 the motor for the ML and GL changes slightly the power output goes up because Mercedes changed the cylinder wall liners and revised the heads this allows 250hp/455tq but also MPG is improved and supposedly the Oil Cooler seals are different (There are still instances of failure). This is not the car we grew up with although it makes identical sounds.

It will last but will require maintenance, if you live in a Hot and Cold climate like Chicago you need/should change your oil every 5000 miles (Its unclear if you should do the filter too but whats a $10 Mann filter, also this might be due to the Bio in the fuel). If you dont do this yourself expect to pay between $150-$200 for this oil change. If you live in a constant climate like SanFran you can go every 10,000 on an oil change but alot of guys still dont recommend. If you do it yourself it will cost you about $80 with filter. The oil is selective in the car due to the volatility of US diesel so after 2013 Mercedes recommended all the OM642 Diesel motors to go to 229.52 Spec oil XW30, not 100% sure why they did this but its important to note. 6 quarts of this oil from Mercedes on Amazon about $59.00.

The biggest issue with Bluetec diesels or clean diesels in general is the lack of readily available Ultra Low Sulfur highway Diesel with 5% Bio or less. In states like Illinois stations are given incentives to offer Bio Diesel instead of Ultra low Sulfur and the bio is at least 20% and it is $.30 a gallon less but will ruin your motor. There are a couple nightmare stories about failed Bluetec motors where the engine oil turns to sludge. The owners have claimed no fault but when the dealer tested the fuel it showed 30% Bio (who knows if the dealer is being honest). Bio will ruin this motor and needs to be avoided at all costs, you essentially pump what is referred to as Diesel #2. This is only available in certain gas stations and you will need to occasionally ask if the Diesel has Bio and how much. This can be an issue when buying used because you dont know if the previous owners followed the instructions or not. Also not a lot of used buyers are aware of the Diesel #2 requirement, so if you are the 3rd owner and the 2nd owner had it for a short period of time it could be an issue.

The bluetec system is the Achilles heel of the powertrain. The emission system essentially chokes the car and cause DPF issues and EGR not to mention errors with the Adblue system itself. If you live where they dont have emissions testing I would have the items disabled and the longevity and durability of the powertrain should increase significantly. You will also make more power and see a 10-15% increase in MPG.

That said, driving a 1st Class ride, Safety and Engineering Excellence for $2.60 a gallon and 745 miles a tank is truly priceless. You get so used to having to pay for premium gas and crappy MPG in any nice European car (with some exceptions). So when you drive the Bluetec (for me at least) I always feel like I am cheating when driving around and its by far one of the best feelings.

 

 

Tires are wearables and consider maintenance,
Rubber air bags are wearables and consider maintenance. (truckers carry spares with them)
Carbon build up in manifold is maintenance item and when you buy 10 years old car for 12% of its original price, you should educate yourself what it takes to keep it on the road for next 10 years.
Sorry you got screw on turbo, but that has nothing to do with the car itself.

 

You're probably better off trying to reason with a block of concrete than some of the members in this thread.

The number of Bluetec related posts tells the story.

 

I agree with Bluetec726 and 84 GTI. Debating the value of a vehicle with someone is like debating politics or religion. Usually nobody walks away feeling like they've changed any minds.
I've paid enough money for high end vehicles over my lifetime to also have developed high end expectations from them. While I do my own maintenance on all my vehicles I've put limits on what I'm willing or capable of doing.

The one thing I don't do is give the manufacturers a pass for putting out an expensive product with major weaknesses and flaws. I don't care if it's MB, Porsche, Audi, Lexus, or anybody else.
Sure, all cars have weak points. The question is "how bad or expensive are the weak points?". If somebody wants to pick up a $60K, 6 or 7 year old vehicle for $10K, fine. In the case of the Bluetecs just be prepared for all the weaknesses you see on this board. If you're qualified to pull an engine and transmission, have the equipment to do it, tear it down, rebuild it, and have the time and place to do it, more power to you. If not, be prepared for a big repair bill.

I just don't buy the argument that it's what most people want from a high end vehicle. Let's not reward or praise the manufacturers for putting out those kinds of products.

 

That sure is original point of view. It would indicate that my huge money saving, while driving MB is religion-motivated?
For years buying older MB diesels I was selling them for more than purchase price, while diesel economy was always unbeatable. Not too many remember, but more than a decade ago diesel fuel was about 20% cheaper than gasoline.
But even now, paying more for diesel, I can do local driving for 2 months before I need to fill up again. Religion?

 

How in the world did you make that leap in logic? That sentence has nothing to do with a persons actual religion or politics. It's a statement that arguments LIKE religion and politics never seem to change anyone's viewpoint. It's a well used analogy. Has nothing to do with one's actual politics or religion.

Anyone else take me reference to mean anything other than that?

 

I dont post much but will chime in here. I bought a GL320 CDI almost 4 years ago now. Specifically didnt want newer Bluetecs due to more complexity and losing spare tire. I have been very happy with the truck during my ownership. I did have to replace air suspension but that was expected and priced in. Unexpected repairs consisted of dead alternator and an auxiliary belt snapping. Main problem though came when the EGR valve backed out from the head. The issue was the threads in the head got stripped. Maybe it was a bad patch of aluminum but a very weird problem to have. Now I have a rally shop at my disposal for working on cars so I was lucky to get away with just a day of work, but if i had to go to the dealer I would have to pay for a new engine as I doubt the techs would rethread a head. So I get the pains for people that cant work on cars themselves or dont have good mechanics.

Other than that problem the GL320 has been pretty reliable and i had to give it to my parents so they are enjoying it now. I missed the good old GL so much I just picked up another for myself, this time a gas 2010 GL550. So even after close to 4 years ownership of the seemingly dreaded (at least on this forum) GL I went ahead and bought another one. Would I buy a bluetec? Highly unlikely due to a variety of reasons, main one is sludge due to higher operating temps and inadequate maintenance intervals. But the GL320 will stay in the family until it dies, hopefully not anytime soon.

 

Unfortunately you can't buy 60 mpg diesel without it being Bluetec.
Than I4 engines are way easier to work on. I just did DPF purge last week.
Removing top covers and pushing the airbox on side (with computer on top) took like 90 seconds and the only tool I needed was 6mm socket to loose hose clamps.
Top of DPF right in front of you with convenient sensor access right on the top.
Same job can take hours on V engines as you have to go under the car and deal with side sensors.

 

I can count the number of major OM642 issues on one hand. And with he exception of oil cooler seals and DPF related issues, the om648 shares every one of those problems.
The timing chain tensioner failed on my om648. The HPFP failed on my om648. The swirl flap linkage came disconnected on my om648. 648 has issues with EGR's that the 642 doesn't. Power steering hose failed and trashed my PS pump on my om648.

Every one of these engines have issues because they're complected beasts. I have a 2005 E320 CDI, 2007 E320 Bluetec, and a 2008 ML320 bluetec, and i wouldn't drive anything else. i love them, and i love wrenching on them.

A disclaimer should come with any 2005+ benz diesel saying that you better be expecting to do at least SOME of the wrenching yourself if you want to enjoy your ownership experience. XD
Do your research, calculate the cost of repairs on every major issue possible, and factor that cost in before buying.

OP got screwed on that Turbo BTW, new turbo at the dealership isn't any more than $1,500. Total cost with labor should have been half what he paid.

 

The biggest issue with Bluetec diesels or clean diesels in general is the lack of readily available Ultra Low Sulfur highway Diesel with 5% Bio or less. In states like Illinois stations are given incentives to offer Bio Diesel instead of Ultra low Sulfur and the bio is at least 20% and it is $.30 a gallon less but will ruin your motor.

At every fuel station in the country with a diesel pump/s the fuel dispensed is only ultra low sulfur diesel fuel. It is illegal to sell anything else. The bio content is dependent on location. More in some places, less in others.

BluTec owners need to be vigilalnt when fueling so as to not pump bio diesel more than 5% bio.