[QUOTE=Vancity;5118740]Ask for another bluetec loaner or demo with the update, take it for a test drive and see if the power & lag are still noticed. Mines got great jump from start no lag, I love the torque. I'm finally now giving it more throttle since I waited to for the break in period at just over 1500km.[/QUOTE

good idea, vancity. I will definitely get a demo and see if it is the same. If not and the demo is better it will be more beneficial then me trying to explain the issue.

How can an update be installed wrong? A Software update seems to easy and be an all or nothing update.

Also, why would they change the operating parameters past a minute or two of warm-up unless they are trying to cover something else up? Maybe they are finding problems with all that torque limiting transmission life or even engine life.

I wouldn’t find anything they do surprising now.

A friend of mine will be taking possession of a Bluetec tomorrow, I will ask if he notices any hesitation or bucking while in cold start. When I mentioned that some people are having problems at cold start he didn’t seem deterred or bothered. Mercedes seems to be still rolling them out of production fast, there is a huge demand. The Majority of the 350’s sold in Canada are Bluetec, I believe something like 80% and regular gas & diesel prices are at par in most areas here…

It bothered me enough to quickly trade up to a 550 which is fantastic. People who say they are not bothered by it are crazy. I wouldn't put up with it and if anyone I knew was shopping for a new ML I would try to steer them towards a gas engine until the problems properly fixed, something I don't believe a software update is going to do.

I would put money on a class action lawsuit in the near future if they keep selling this model with a known problem.

Question is, what is the percentage of Bluetecs with this problem?

All the posters her have had this problem to some degree, but how many Bluetecs are out there without this problem? I have not had any of the myriad of problems (touchwood!) described here any on other boards - hope it stays that way for me!

I have my ML350 Bluetec for a month now and it does bucking after getting out from my driveway for the first 15 seconds or so. After that its back to normal and no issue for the whole day. Provided that this only happens on cold day and it didn't occurs to me anymore these days cos of the weather is warmed up in Vancouver. This problem not bordering me at all and I do not have the software update and I don't think I need one. I know a cad$73000 car shouldn't be like that but to me this problem is very minor and I can live with it.

2011 BMW 5 series has had a similar issue with a .5 to .75 second delay when accelerating from a stop (I know, I have one). Finally over a year later BMW has a software fix which completely cures this issue. Until then the dealers were denying there was a problem and could do nothing to fix it... sounds very similar to this bluetec issue. I wonder if it affects the W212?

I spoke with my service manager today after he spoke with MB engineering and he stated that MB has not heard of anyone with a turbo lag issue after the upgrade. scheduled another appointment to look over the car next thursday so we will see what happens.

Unfortunantly, my dealership does not have another BT on the lot to compare against.

I told my dealer I could care less what other bluetechs do that are on their lot. I was only concerned about my car. Don't accept the dealer telling you its normal. Because that is what they will say.

I was "lucky" that the Service Foreman totally agreed with me and that made it very clear to the Sales folks that they better help me out and get me into the 550.

picked up my ml bt last night and it didn't hesitate or buck.It was warm though because delivery is in heated garage

In Canada here. Picked up ours 2 days ago and so far experienced none of this issue. (knock on wood)

i have had the truck for 1 1/2 weeks now its got about 900 km./550 miles i left it outside last night weather around 32 here and it did not buck or hesitate.as a matter of a fact it never has since i got.Did i get lucky or have they fixed the issue?build date was 3 rd decade february.It ran at about 10L per 100 kms/ 23.5 miles per gallon.premiun gas is a bit more expensive here than diesel here around 20 to 30 cents a gallon, love the bt and would order again any time.

My 2011 E350 Bluetec needs a bit of a warmup before it becomes smooth. It can jerk a bit at low speeds when near idle; I usually tap it into neutral while waiting for the garage to open, rather than coasting forward in gear.

By the time I'm a block away (i.e., the engine is warming up) it's gone, and I have never considered it a defect.

I wonder if the extra power they're getting from the engine in the new ML compared to the E could be exacerbating the effect.

The only thing I find is that the transmission doesn't want to shift to 2nd till about 2200RPM. Seems high but only for the first 30 seconds or so then its back to normal. But all in all its OK now after the update.

It's the same with my '06.

Typical for diesels. The shift points are raised initially to speed the warm-up.

Its a planned thing to warm the engine sort like the old and still fast idle. VW similar. That's a lot of torque from a cold engine and some complainers here have never had a diesel and that much grunt on a cold morn. All things like people need mods and adjustments. That's why mullets are still around LOL

Took delivery of mine April 7th and I have not experienced this issue at all. We have even had a few days in the -2 Celsius range and no hesitation at all.

It was great the first couple of days, then midweek it stumbled huge on my way to work. Was in DC this weekend, pretty warm, and it stumbled again. I have been driving diesels my entire adult career. I know what to expect in the morning, but that stumble is disconcerting...

Yep, your car is infected. You need the update. That should cure it.

Anyone with the turbo lag after the update get any fixes or answers? I'm taking mine in tomorrow. Over the phone they said 'that's how diesels are', but I don't believe it. Mine is similar to what someone else said with it hesitating and then almost jumping forward. When I'm at a stop sign and cross traffic doesn't stop, I wait until everyone is gone because I'm afraid my car won't go in time and get to their speed.

Semi-OT, but I noticed my E does that if I'm using cruise (the automatic one with safe-follow distance) from a stop and the car in front of me is accelerating. Shift points are all annoyingly higher than if I do it myself.

I took mine to the dealer last Thursday and everything checked out OK. The shop foreman and service manager drove the car and said nothing seemed out of the ordinary but they did not have another diesel to compare it against. They have a new BT set to arrive the first of May and we can compare. Until then I take the same procautions as you.

AFTER ABOUT 1200 MILES ON MY BT IT HAS STARTED TO F**K BUCK WHEN COLD!!!!! DAM IT