tjg0024

Mine got done. It's better when the engine is warm, but there is still a problem when the engine and weather is cold. Still hesitates and bucks. We had some cold weather here last week and it was really noticeable. Now that the update is done, my service advisor said there are no more updates coming for this car. There is a flaw here. My 2010 Bluetec did absolutely nothing like this. It's going back in tomorrow...

Vancity

I thought it did the second day but I think I was looking way too hard at finding the hesitation, if it did it isn’t as bad as before. I also have been parking my ML inside my garage since it came back. This morning there wasn’t any hesitation at cold start. I will monitor it more closely the next few days and see how it goes...

Vancity

Are you taking it back so they can try to address & correct the problem or is it going back for good?

lisa00

How's it going with it?

I finally picked up my ML 350 BlueTEC on Sunday after it being on order since October. I told my salesguy that I was nervous after reading all of these comments but he was acting like it's not a big deal since diesels need time to warm up. Of course the day after I pick it up, I see exactly what yall are talking about. Then this morning I wanted to see how bad it is so after leaving my driveway, I gave it a lot of gas and it was even worse. It's fine about 30 seconds to 1 minute after driving but that's not really acceptable. And my car sits in my garage so it's not like it's cold in there, only when I get out of the garage.

I made an appointment on Thursday afternoon to get the software fix, so I'll know Friday morning when my car has been sitting a while if it works or not. Fingers crossed.

For those that have traded it back in, what did the dealer say when you said you wanted to return or exchange it and how did you overcome it?

dgiturbo

Should ask the sales guy why the 2007-2011's diesels don't have this issue and run just fine from cold startup.

2012MLBlue

It's so blatantly criminal that they keep delivering these vehicles with a known problem they are trying (apparently unsuccessfully so far) to fix.

To answer your question I wrote several emails including one to the owner of the dealership that I was prepared to get my lawyer involved and send a mass email to thousands of local business people I have in my contact list about it. That was all it took to get the paperwork flying and the 550 deal closed.

Loving this 550 so much that I wish all of you with the diesel issue could trade up into one.

Markled

If you let the engine idle for a minute before pulling away, does the issue still happen? (Just curious)

caf

Glad you're enjoying your 550, but I can tow my 6000 lb. boat with ease, and get 24 mpg in suburban driving. The minor stumbling I occasionally get for a few seconds is not that big of deal on my vehicle. No way I'd trade. The diesel is really the only reason I got an ML. If I wanted a V8 I'd get a Cayenne. Handles much, much better than any ML.

2012MLBlue

I've had both and loved my 08 320 CDi. I also have a boat and with trailer loaded with 200L of fuel and gear its about the same weight as yours. The 550 has the same tow rating and similar torque so I have no doubt it will tow well.

As for the Porsche, I haven't driven one and the closest dealer for me is a 45 minute drive away on a good day, too far for me. It likely does handle better but I live in the land of flat, straight roads so comfort is far more important to me. I also feel like the Porsche is a bit too flashy for me, the ML represents more family values, solid, safe and (should be) quality.

As for accepting an engine problem with a new luxury vehicle, you are way more relaxed than I am. I wouldn't (and didn't) put up with it for long.

GregW / Oregon

For 2013 you will be able to choose a diesel Cayenne (or Cajun). The 3.0L V6 makes 240 hp and 406 lb ft in the current Euro version.

caf

Yep. I thought about that, but couldn't wait that long for a vehicle. If I was going to buy later this year I'd consider both the Cayenne and (gasp) Jeep Grand Cherokee diesel.

lisa00

So I tried this this morning. I was actually idle for 5 minutes as I tried to figure out how to work my nav system. Left the garage and sure enough, bucking happening all through my neighborhood.

I let my car sit for 1.5 hours while I ate lunch and when I came out, it worked fine. So I don't know how long the car has to sit for it to do it.

Vancity

This morning I had no buckling, I was out of the garage in 30 seconds. I do notice that the engine is a lot louder when cold and it does take a bit longer when getting out of gear. There really wasn’t any hesitation but its rather not smooth shifting when it`s cold. It definitely quiets down after driving for a few minutes and shifts smoother when warm.

This is my first diesel, so I'm not sure what to expect. Do diesel engines take longer to get going compared to gas? I`m beginning to think that Diesels really do not like the cold...
On another note, when idling (in park) I notice a faint ticking sound, which occurs every 5 seconds, it goes away then comes back. It appears to be coming underneath the door sill. Is this normal?

Now every little thing I notice after the hesitation issue sets me off.

serge01

i have had ford diesel trucks since 1998 and i can assure you they do not buck/hesitate when cold, they are louder when cold i think.My mb btc should arrive in a about a month and i can`t wait. ordered btc because i love diesel engines but with all comments on btc i admit i am a bit worried and when it arrives weather should be warm enough i fear if it has the problem i will only find out next fall.

katiesdad7

I'm still getting the hesitation even after the update. I am also getting a vibration at 45. This happened after the dealer did a software reload on the first service visit. During the second visit they said they can't duplicate it and did nothing. Now after the update and 3rd visit it still vibrates and now makes an intermittent thump when starting off or slowing down.

Lemon law is my next step since MBUSA will not return my calls.

dougiebear

Dudes New design BT is new as in 00 to low mi/km and high compression cold tight new tech motor. It will settle down. Don't treat it stupid and it will work hard for You forever. My VW tdi 06 was a bit stiff in sub frozen but it just broke in at about 220,000KM as I get the best mileage NOW. Even some gassers get cranky when its cold as some of our Canadian spots get. But in Niagara Area I have not heard of a 2012ML BT cold rumble story yet. Just saying they may be there but I haven't heard any. 80% here are BT Diesel. Be gentle LOL

DC-IT

I wonder if you drive it like you stole it if the hesitation disappears?
That is how I drive my three Diesels and I'm loving them more and more each day.

longisland516

As a new 2012 Bluetec owner I am disappointed that Mercedes did not solve this problem. It can be dangerous as the engine actually cuts out for a short period then resumes. It seems the torque converter is locked or has little slip as you can really feel the car buck when the engine cuts in and out.

It is not fuel quality or a transmission problem. As most owners state it is related to engine temp. If it is very cold out extended idling does not help because the engine does not warm up fast. In short, it seems as they are running the engine very lean for emissions. If that is true, then there might not be an easy fix that allows the engine to meet emissions laws, but I would still expect them to fix it.

Does anyone know if E or S class owners have the same problem with this engine?

I don’t see this going away with time or miles and I don’t want a 350 or 550 gas ML. My last ML was a V-8 and the fuel savings is significant with the diesel. In some cases, such as, a lot of in-town driving, the mileage is nearly double with the diesel compared to the gas V-8.

Has anyone just returned it to the dealer and got a full refund so they could buy another brand?

Vancity

Wouldn’t they have to meet the same emission requirements in pervious year ML Diesel models? Did previous ML Diesel engines also have this same problem?

DC-IT

My 2011ML350BT doesn't have this hesitation issue but it has the auto-lighting issue where the headlights will come on in bright daylight with blue sky and there is no fix.
M-B explains it as the Blue Sky Effect and said to put up with it!

BTW, the 2011 and older ML has a different Diesel power train which make only 210 HP/400 Lb-Ft TQ.

If this issue is not corrected I guess I'll stick with my 2011 ML when the lease is up in 2014 or I might go with the next x5 Diesel.

Too bad I was leaning towards the new ML BT.

Vancity

Does anyone think that this problem is only in North America? As all the ML’s for production are built at the Alabama manufacturing plant.

Do you think that they are experiencing this issue in Europe or Asia also?

300DTurbo

This is an amazing new Motor! (triple turbo diesel) That will be the next purchase.

GregW / Oregon

Funny that the auto lights work fine on my '06 ML. (though, even better on my BMW). So they forgot how to engineer this system in the last few years?

DC-IT

Yeah that's awesome.
Maybe they fired that engineer?

Sorry lets not hijack this thread to other topics.
Here's the link to view my thread on auto-light:

https://mbworld.org/forums/m-class-w...s-erratic.html

lisa00

Happy to report back that the software update seems to be mostly working. There was no bucking this morning as I left my neighborhood and I gave it a lot of gas to see how it would handle it. There was one part at the very beginning where the car hesitated and I wonder if that was between 1st and 2nd gear. Other than that, I didn't notice any problems.