I have a 2011 that we picked up as a CPO 3 months ago with 10K miles on it. It is a Bluetec Diesel and all has been well until this week. We are on vacation in Crested Butte, CO (altitude 9000 ft) and since we arrived the car often idles roughly when in gear (when you are at a stop light, preparing to exit a driveway, etc.). If you put the car in park, no problem but in drive it seems make more noise and you can feel some vibrations. The car can be warm or cold. . and it doesn't always occur. We had no issues at all on the drive up.

This is new. It never occurred in Dallas (where we live and drove from, elevation 700 ft). Could this be related to altitude? Any other ideas?

Thanks
Adam

 

It actually might be a failed motor mount. Does it matter drive or reverse as to whether the vibration is greater?

 

I did have a problem last summer at 5000 ft, when a cold wind blew and the fuel waxed as I did not have winter blend. But the vibration was mainly from the fuel pump in the rear.

 

my ml 350 basicly did what you are describing. Is you MB past it service date ? I was talking to a guy in my area and he claims this could be the problem.. i cant see it but im just asking to try and figure it out ... mine is going to the shop today . if they find any problems i will post it back on here ...

 

I've only had my Bluetec "at altitude" once...last month...and only for a day.Drove from Denver to the top of Mount Evans (14,000 feet).Everything went very well,much better than I had expected.Nothing even remotely resembling what you've described occurred.Of course I'm a flatlander from the East and this was my only high altitude experience in *any* car so....

But my experience just might suggest that what you experienced isn't normal (for a Bluetec at least).

 

If it was the altitude, it would do it every time, not just stopped in D. Hopefully your check engine light came on so the cause can be traced easily.

 

No check engine light.

 

Then I would guess poor quality fuel at your last fill up. May have a little too much water in it. Try a Cetane improver like Power Service and see if it improves.
I am also basing my thought on the fact that this is a 2011 CPO, and the dealer actually did everything on the CPO checklist before delivering to you.

 

Thanks. I am greatly confused by diesel. . .which one to use, which is better.. . they all say "Ultra Low Sulphur. . ." but is one brand or station better than another?

 

Higher Cetane better. Typically find a station that high volume sales. Best chance of the fuel not being stale.

 

Ok - so the problem never went away at altitude, however, I never burned through an entire tank of diesel - barely half.

We left last Friday and by the time I filled up (at 5000 feet) the problem was gone and hasn't returned.

So not sure if it was bad diesel or altitude but it is gone with no CEL.

 

If it were me I'd report it to the dealer on the odd chance that they'll find a fault with their computer.And even if they don't you'll have the event "on the record" in case it returns later on.

 

We have been experiencing the same problems with our 2010 GL 350.
Bought the car new in 2010 and took it on a summer trip up to the mountains in Colorado within the first year. Once we exited the highway and came to a stop light, it started shaking like it was going to stall out. Not a minor vibration...the whole car was shaking. Put it in park and it stopped. Continued to do this every time we came to a complete stop while in drive. No check engine light and took it to Benz service and it didn't pull any codes. MB service said it must have been bad gas. We live in the Denver metro area and have no problems with it in town at 6,000ft. Drove back up to the mountains last month for the second time we have owned the car...same thing happened again. Took it to MB dealer and no codes or check engine light. MB said it has heard of this in a few instances and a software upgrade fixed the problem and they were sure it would work. After software upgrade, took another trip up to he mtns and same problem! Took it back to MB service and they said they test drove it to the mtns and the problem reoccurred for them. They said they thought it might be a bad sensor so they replaced the sensors and took another test drive back up to the mtns to only have the problem reoccur. MB service said they have been in contact with MB and that there are reported instances of this with the blue tech GL's. However, they currently do not have a fix for the problem and said MB engineers are working to develop software to fix the problem. They also said it could be weeks or months before they find a fix! This is ridiculous for an $80,000. car! We bought season ski passes this year, so I guess we will have to rent a car to go skiing on the weekends until MB finds a solution. My husband thinks it is a problem with the transmission and or torque converter.

 

I wouldn't call it "shaking," but ours occasionally goes into a 900 rpm idle and the throttle response is goofy. This has happened at 11,000 ft, 9500 ft after 10,500, and at 7500 ft. (We live at 5200 ft and normal idle is 750 rpm).
The first time the Dealer thought it might be bad fuel, which made some sense since we had filled up at a small Shell station with low traffic, so we agreed that it might be possible.
The third time, again just before a service, we were told the same thing, but this time it didn't make sense. We were half way through a tankful and the problem only lasted for about 1/2 hour. Same fuel before and after. Same local station - we try to fill up at the same local station - new tanks, high traffic, Shell.
So this time I don't buy the "must have been bad fuel" story. I suspect there has been a technical bulletin circulated by M-B that passes my symptom off as bad fuel.
Anyway, I have reported it, I have a record of all my fuel purchases, and I feed the Dealer's profit center by allowing them to use their fuel additive when I have service.
I did have the software update before my last episode, but I was told that it was primarily for recalibrating the AdBlue rates of injection. We'll see....

 

Hi, Mikapen. Here's an update on my GL. It has been at the local MB service dept since last week. MB USA has an open TAC case on this problem and they do not have a fix yet. My local MB service manager was told by MB USA that it could be weeks, months or possibly up to a year before MB engineers develop software to fix this problem. Bluetecs that have this problem will never know it if they do not live or drive in higher altitude (9,000ft). My local MB service dept has been trying to get info about 2 other bluetecs in Colorado Springs with the same issue. MB USA has recommended the valve body and torque converter be replaced. Local MB dealer is working on this now and will test drive up in high altitude to see if it fixed the problem...supposedly, it's a 50% chance.

 

2irish,
The expected transmission fix seems off base - my problem persists in neutral. And I can't replicate the problem. I often drive over 8500 - 10,000 feet and the symptoms only appear occassionally. Maybe 1 out of 4 or 5 times. A single test drive to high altitude, with my experience, would likely not duplicate the problem even if was not fixed. I would have low confidence of a successful repair.

The car also does not save a fault code for the problem.

In more primitive times, with my '85 TurboDiesel Jetta, I'd get out and drain the water from the water trap with the handy drain kit that came with the car. It would act up every 15,000 miles or so and that would fix it....

And that could be the problem. I am not as good as I should be at keeping the tank on the "full" side because I revel in the 550 - 650 miles per tank around town.

Maybe I should go back to filling at 5/8 of a tank. That would dollar-cost-average my fuel costs, now that diesel is on the rise again!

 

geez, all this sure makes me happy that I didn't get a BTC after all. I special ordered an '11 with BTC, but changed my mind just prior to production and went with the gas 350.

I'm sure there must be many BTCs running around high altitude w/o problems, but it would be just my luck to draw one of these problem diesels.

 

eeferber:
Ha! Then you are putting up with the limited power, fuel economy and complexity of the gas engine! (just kidding)
The gas cars are not without their problems, either - we were laid up for a week in Spokane (C240) while they worked to discover and finally fix the cam position sensor.
And we won't have to pay the super high cost of replacing a dozen hard-to-get-at spark plugs!
I think if you scan the threads you will find relatively few problems with the diesels - in this place where folks post their problems.
I have had a lot more problems with my NAV at high altitude than I have had with my drive train!
The biggest problem may be that the service folks don't have the familiarity with diesels that they do with gas. Maybe that will change.

 

I too had a NAV problem at high altitude. MT Evans - after parking and hiking the final couple hundred yards to the top, my NAV wouldn't boot up when I restarted the car. Don't recall what the error message was. Stopped for lunch in Idaho Springs and then it was all fine again...?

Oh, I understand that diesels are reliable for the most part -it would just be my luck to get one of the problem ones.

Actually, I fearing the worst with my gas model when I had 2 CELs before the odometer broke 800miles. Fortunately, it's been problem free since.

 

Update on the 2010 350 bluetec GL shaking at altitude:
The new torque converter and new valve body fixed the problem...have had the car up to the mtns 2 times in the last 2 days and it hasn't repeated...and it did it every single time prior to he fix!
Bad news is on the way o go skiing at Winter Park, we got a "Drive unavailable -temperature too high" message on the COMMAND screen and no systems will work...no phone, no nav, no radio, etc... I did get this message once before but thought it was a fluke...guess not.
Any insight into this?
Thanks!

 

that message sounds familiar to the problem I had @ high altitude - see post #19. Mine cleared up when restarted at "lower" altitude and never reoccurred.

 

Good news on the torque converter.
The "Drive not available" message is what I mentioned on post #18, above.
It is referring to the "hard" drive, not the automobile drive. It has caused me to pull off and park at turnouts after climbing some passes until I verified what was going on. I pressed the "I" button and got help from tech support.
My first experience was after Kenosha Pass, 10,000 ft, paved.
At the last Star Trails in Ouray, CO, we crested a 4WD pass (Imogene Pass, 13,000 ft) to find an ML with the hood open, people gathered around, fanning the engine compartment. They were relieved when I shared my findings.
Once the message goes away, everythiing seems to be OK.
My opinion is that M-B needs better ventilation for the NAV system and a more descriptive message.

 

that's pretty funny!

granted the error message is somewhat misleading, but it should be rather obvious it's referring to the inoperable Nav system....

 

Thanks for input, Mikapen and eeferber.
We knew it was a COMMAND system problem and not engine issue, so we didn't pull over Doesn't make sense why the COMMAND would overheat after just a 1.5 hour drive as we have had it on very long, hot summer road trips prior at low altitude without this message. Also, sounds different from what others have experienced as the entire COMMAND sys became inoperable...no radio or anything. Weird though, as my boys were watching a DVD on the DVD players in the back and it didn't interrupt or shut off their movie.
I have had the entire COMMAND sys power off on me twice in 40,000 miles...both times just driving around town and both my hands where on the wheel...so I wasn't pressing any buttons to cause it. The COMMAND didn't display a message or anything...just shut off...reminded me of Poltergeist.
Each time, I was able to power it back on with no problem.
I have searched the forums here and didn't find a post with the exact same issue as other posts only had the NAV inoperable. I will be calling my local MB service Monday and have them look into it...thinking it is possibly an electrical problem with the COMMAND?

 

I think our entire Command didn't work, but it's been a while and I don't know how much troubleshooting we did.
My guess is that the thin air doesn't draw enough heat out of the unit.
We've been in 112 degree weather but no problem. (Pulling our 27' travel trailer, too.)
Just the altitude woes. Do Poltergeists only live at high elevations?