You only would want a used BlueTEC if:
1) you need to tow something
2) most outings are >45 min of highway driving

The Diesel will get you better mileage but the maintenance and repair cost of the AdBlue/BlueTec will be greater than what you will save in fuel.

But whatever you decide, get it from the dealer as a CPO with the extra full warranty coverage. I have had my 2010 BT for less than 4 months now and the warranty has already covered over $8k in repairs... And I still have 2 years left on it...

 

Purchased mine about 9m~1yr ago (100,000k on the clock) , 30,000k so far and nothing more then oil/filer changes and regular maintenance so far.....according to the service history this one has been well taken care of, always dealer service, had the oil cooler seals changed already.....we will see in a year or so how everything is heading....

 

Around here gasoline is under $2/gallon and a few stations have diesel for just under $3/gallon. One posts $1.999 for regular, $3.599 for diesel. I observe diesel lags gasoline prices by at least 3 months. Bad when prices are falling but when rising gasoline often shoots up above diesel.

When ULSD is only 10% more, or something close to premium gasoline prices then you could save money. But not today.

 

Diesel will stay high in the winter because #2 diesel and home heating oil or the same (some suppliers of home heating oil add #1 kerosene for above ground tanks) and the demand for that has been very high recently. Also one barrel unit yields about 12 gallons of gasoline and 19 gallons of gasoline so their will always be more gasoline as crude oil is refined from every barrel.
How many gallons of diesel fuel and gasoline are made from one barrel of oil? - FAQ - U.S. Energy Information Administration (EIA)

 

Here was a good article i read a while back regarding cost of ownership of different vehicles, gas vs diesel....

Diesel Analysis


http://www.dieselforum.org/files/dmfile/20130311_cd_umtritcofinalreport_dd2017.pdf

the only real issue I have found with my bluetec at lower rev's in lower gears the transmission has issues deciding what gear to stay in....so there is some jumping/studdering. I had it into the dealer and i goes its known as "realator syndrome".....seen on many blueteks....supposedly....and nothing they can do about it. I have seen a few posts on the forums here about it. I find that driving it a little more aggressively , this doesn't happen!!

 

I had my 2011 BlueTec for about 18 months now. Before, I owned a 2003 ML500, which I really liked.
But the Technology between those two are worlds apart.
With the 500, I had to go fill the Tank every week for $85.00.
The Bluetec needs $75 now, but only every three weeks. Amazing.
The Ride is completely different, Transmission is very smooth, power is plenty.
Full leather interior, all options I can even think about....heated Steering wheel in CA? Don't need it but nice to have.
I love the Shifter on the Steering wheel, and all those electronic goodies like Blind Spot assist, Rear Cam, Air-conditioned Seats, etc.
The list goes on.
Anyways, I've been driving Mercedes since the late 70's, and this is the best I've ever owned.

 

Wow - quite a mix of pro and con experiences. Sounds like the oil leak pertaining to the oil cooler and turbo fittings is by far the biggest concern. Also sounds like the Viton seals, while an improvement, are nor a guaranteed solution to the problem.

Appreciate this insight from current or former owners of 2010-2011 ML350 Bluetec's , please add to the string, trying to get a clear picture before deciding between an ML550 (thirsty) or an ML350 BLUETEC ... thx

 

Well, last month (around Christmas, ouch!) I plunked down $4400.00 for the 100000 mile warranty, so got some time to go before I start worrying about Oil leaks.
Tons and tons of Sprinters are running around in Germany with the exact same Engine, and don't seem to have problems.
My Brother's Sprinter (in Germany) has the 3.2 l Diesel in his and happily crossed 300000 km in his. (190K miles).
I do worry more about all the Electronics, if they go out and have to be replaced, or the actual Turbo on it....

Finally, in Germany 48.1% of all newly registered Cars are Diesels.
Link.

Btw, someone mentioned the "Cost of Adblue", lol!
If you complain about buying Adblue every 10.000 miles for a mere $30, maybe you shouldn't drive a Mercedes after all.
'Nuff said.

 

I current have 58,000+ miles on my 2009 ML320 BLUETEC that I purchased new. I can't speak for other owners, but I've had nothing but trouble with this vehicle from day one. Its been at the dealership countless times, check engine light frequently on, and has left my wife and I stranded several times. It did/does not qualify as a lemon because, to be a lemon, the "same thing" has to be wrong with it several times. With this truck, many "different things" have gone wrong. After awhile, the service department was/is tired of seeing me, but not half as tired as I am of seeing them. Buy something else.

 

You want my honest opinion? Here it is from another post:

[RANT]
This Merc is by far not the fanciest car I've owned (under my belt are an Audi A8L, an E46 M3, the twin-turbo 3000GT, three A4's, an S4, A6, Cummings TDI Dodge Ram...) I have NEVER paid as much for a car (by half) as I had for this low-mileage, late-model Benz. I've also never owned a car that had been such an utter piece of crap and has been this impossible to work on. I've had it for about a year now...

- The passenger front door power lock stopped working.
- The driver's seat lumbar fully inflates itself every other time when the car is parked and locked (fun, huh?)
- The driver-side headlight throws a CANBUS error every 3rd time and refuses to turn on.
- Speaking of headlights... having to remove the F'n bumper to change a side-marker bulb?! What were they smoking when this design passed the drawing table?!
- The Glow Plug Module failed. Upon examination, the design looks to be modeled after something that I've seen described in a book as, "an improvised time-delay electric fuse".
- But all of that pails in comparison with the genius decision to put a high-pressure oil/coolant heat exchanger in the back and deep in the V of the engine where it takes 10 hours of labor to dig down to...

The thing that just absolutely pisses me off however, is that I feel like I am blind. There are no diagrams online. No write-ups in forums. Nobody seems to know where anything is on these things, how it works or how to test it. All I am finding are posts of guys talking about which shop they took their cars to and how much they paid for X. Those that are working on their own cars are swapping parts and sensors seemingly at random with no procedures posted or troubleshooting data. There is virtually no technical information out there! This stuff is not rocket science! If there is a sensor, there should be a relatively simple test procedure for it usually involving an ohm-meter. But forget about ohm-meters - I can't find the damned components!!

EVERY other car I've owned, the online communities (like this one) have been treasure troves of information. A decade ago when I was heavily involved with the 3000GT VR4 and the Audi communities, we had access to factory manuals and super-granular troubleshooting information. Some of us got so good with this stuff that DEALERSHIPS would call us (me) for advice or clarification of our posts.
[/RANT]

 

If you can find one that had the oil cooler seals replaced, you should be in good shape. Just keep an eye on the turbo seal and keep in mind a potential shock replacement ($4xx for a front pair of Bilsteins).

Knowing about these pending issues ahead of time should avoid surprises and you can add the replacement cost to your purchase price.

I can also confirm that gas mileage is only good on longer drives. If your commute is sub 10 miles, it won't be worth it as you will only get high teens. Long distance fwy, you will get 25+ (depending how fast you go). I only use this vehicle is my back-up car and road trips, so it works well for that. If I wanted a bullet proof daily commuter, I would probably buy something else.

 

Long distance fwy, you will get 25+ (depending how fast you go)

Sorry to hear your mileage isn't what it could be.
I travel Orange County frequently and getting almost 30 mpg, on a 25 Mile Trip.
(Long Beach to Anaheim Hills).

Around Town, it is always around 23-25 mpg.
There are more factors coming in about mileage, the way you drive is a big one.
Tires not properly inflated, carrying too much junk in the Trunk, AC on or not, etc.
The List goes on.

 

Well, I have the '08 CDI (pre-bluetec). Same common problems but I believe the mileage is rated slightly lower. My combined mileage for the last ~ 5k mi was about 24mpg. I posted 25+ fwy since it really depends on the terrain and the way you drive. I did 600mi this weekend. I had a little over 23mpg on the way up (traffic + lots of uphill). I averaged 28.3mpg on the way back (a lot more downhill and no traffic). I typically do about 75mph; I know 65-70mph is better for mileage.

 

Amen to all of that! Every Mercedes design engineer should be required to spend some time working on these things.

 

I honestly don't think that this is the problem. German engineers are not stupid people. I read an article some time ago regarding some museum that was trying to restore a WW2-era German fighter. They were searching all over the world to find a machine shop that could manufacture a replacement crank shaft for their engine and were unable to find anyone because nobody could figure out how to replicate the thing with the required degree of precision.

A novice designer with basic knowledge of how these systems are typically made would throw up every red flag they had upon seeing the oil cooler design on these things, or the glow plug relay module for that matter. This is not an "oopsie". It's done on purpose - there is no other explanation.

They want to build in outrageously expensive repairs into the design as to encourage people to buy a new one. The problem with that strategy is that it destroys the resale value and thus the incentive for smart buyers (even those who can afford to buy a new one every few years) from buying one. Fact is, many people in that income bracket are surprisingly bad at math and I am seeing this trend happening across multiple German brands. F'n Audi with their plastic water pump shafts... And requiring a $2100 timing belt job to be done in order to change out a $30 thermostat. Don't get me started!

Just think though: Not so long ago MB was a company with an active million-mile club. Utter garbage now and I got suckered into it trusting in the brand.

 

Unfortunately, you're probably correct. I, for one, will not buy another one. It's the old "fool me once, shame on you; fool me twice....." thing.

 

I honestly think they just sourced the seals in this engine from a new supplier and got burned on it. It's obviously a material that doesn't last very long. I see it as a QC screw-up. I doubt they purposely put in crappy seals so they would fail.

Time will tell if this vehicle will hold up. I plan on putting at least 150k on it; part of the reason I bought a diesel. They are supposed to run forever.

 

I honestly think they just sourced the seals in this engine from a new supplier and got burned on it.

No way! There is no reason whatsoever for an oil cooler to even be where it is on that car!! It's put there on purpose to be a pain in the ass.

Oil coolers become a necessity when you are talking about a car of this size. But how does EVERYONE else out there do it? I've dealt personally with Mitsu, Dodge, Ford, Audi and VW on this specific subject matter. Most of the time, you have oil lines coming from the front of the engine near the oil pump that route the oil to a small radiator mounted either behind the grill, or off to the side. Another design I've seen is a heat exchanger, much like what MB had done here, but it is built into the main coolant radiator, again up front. On most cars these can be changed out without removal of the bumper and with proper tools/experience be completed in less than an hour. They are also usually changed out due to the potential of sludge buildup that inhibits cooling - NOT leaks! Matter of fact, I've never seen an oil cooler, or it's lines spring a leak unless it was due to physical damage. The biggest PITA cooler that I've seen (Mitsubishi 3000GT VR4 Twin-Turbo) would not take more than 2.5 hours to change and that is only because of various covers and cowls that most tuners toss in the trash.

Putting the cooler in the back of the engine and deep in the V makes about as much sense from an engineering standpoint as putting the steering rack in the trunk!

Secondary to the obvious design flaw are the seals. Whatever seals they used are obviously crap and conveniently fail like clockwork typically shortly after the factory warranty period. Routing of oil to coolers is not treading new ground! Fittings have been in existence for longer than I have been alive that are time-proven, inexpensive and efficient. You are drinking coolaid if you think that this was an accidental error!

Finally, you are going to be proud of your rig if it reaches 150K? Seriously?! My Cummings-based 2004 Dodge TDI has 210k on the clock right now and drives/runs better than the new models. I know guys with this gen truck that have already (with some rebuilds, but on original block) clocked over 800k - they run 400k+ normally without major rebuilds and are much more abused than this glorified soccer-mom-mobile.

Not only is the MB CDI line utter crap. I would go farther and say that a company that could let a car like this roll off the assembly line, has something deeply wrong with its vision. This is literally the last MB that I will own.

 

I guess the Chrysler team designed this one LOL Parts are definitely in odd locations; just changing the air filters is way more work than it should be. Typically 2 minutes on most cars. Since a lot of people change cars every few years, they probably didn't bother putting everything in a convenient location for repair. Sad but probably a trend in a lot of modern vehicles.

I'm not saying 150k mi is a lot btw. If it doesn't fall apart, it will just be older than dirt. I have 57k now and average about 7k/year.

 

We bought our ML320 so that when my wife and I retire in a few years (at 60), we could use it to pull our small Airstream trailer across the USA, and that the diesel would give us good fuel economy, and that (being a Mercedes) it would give us thousands of trouble free miles. The way I feel now, we don't drive it too far from home. The times that it has left us stranded, we were able to quickly get it towed to one of several dealers in our city, however, our plans to use this thing for what we intended are gone. There's no way we will risk having "issues" in the middle of the night, hundreds of miles away from someone that has a clue of how to fix it, or get the parts.

 

Out of curiosity, which problems left you stranded? None of the common issues would prevent you from driving. I often drive this vehicle in the middle of nowhere, so it would be good info to have.

 

Total electrical system shutdown. There is supposed to be a small battery that, in case of main battery failure, will allow you to put the transmission into neutral so that it can be towed. That did not happen, so the vehicle had to be put on four wheel dolly system so that it could be towed it to the dealer. Also, fuel pump failure, without warning.

FYI, we test drove many medium size SUV's before we bought this ML. We stiil think that is the best looking, best driving/riding, tightest, best MPG, etc. of all the SUV's. I know that all vehicles will eventually have problems and need repairs, however, we started loosing confidence in it at 5800 miles when the steering column failed and the carpet began to pull away from the passenger door jam. Since then, there have been numerous warnings for, and failures of NOX sensors (at least four or five different times), TWC cat. convertor sensors (eventually convertors replaced), EGR sensors, ESP for steering angle sensor, battery cable replaced, upstream tubo temp sensor(twice), oil consuption test due to high oil useage between 38k and 42k miles (cured itself), etc....all of this before 40k miles. The fuel pump failed at 55k miles. There are other sites and post online that show that many other owner have had these problems with these diesel ML's.

Is the gasoline version better (more reliable)? I'm open for suggestions.

 

Wow, that is crazy!! That definitely sounds like a lemon to me!! I would definitely get rid of it, even if it means taking a loss. Besides the turbo seal and oil cooler, I don't think the gas version is that different.

All that said, these repairs don't seem normal. I did a good amount of research and the mainstream ones are the two mentioned above and sometimes the shocks that leak (still not acceptable but MUCH better than your troubles). I bought my '08 with 50k on the clock and have all the paperwork since new. The only repair this vehicle ever had was replacing the driver's tail light because the bulb kept burning out. That's it.

Since then I replaced the front shocks (one was leaking) and I replaced the turbo seal (more preventative than anything else). My mechanic who has a few customers with the diesel model told me the oil cooler seals is the most common expensive repair he has done. Other than that, nothing major.

I can see why you're upset; this is crazy! Have you researched the BMW X5 35d? That one was on my list as well; I don't recall reading about any major issues with it.