notorius

Hi,

Out of nowhere following problem starting to happen.

- Car stutters around 1100 rpms on slow gas pedal press and then immediately picks up like turbo hits
- Car stutters (hiccups) on slow gas pedal input, jerks and drops rpm. On harder gas press its fine. This stuttering only happens when engine is fully warmed up. happens in almost all lower gears.

i changed fuel filter in Jan/Feb and it was running fine until last week when all of sudden this started happening. Gas tank has been emptied and refilled
No engine light.
Pickup seems fine
Cruising is good
gas mpg is fine.

Transmission oil replaced last year about 8k km ago. engine oil services done.

2013 Gl350 bluetec

Any idea what could be ? Thanks

notorius

anyone pls ?

captivabenz

Perhaps you received some contaminated fuel, your fuel filter is plugged up. Would be an easy check to replace.

notorius

i changed fuel filter again and still same issue.

Another user on a forum posted same issue :
I have noticed sudden loss of rpm( I have 2013 GL350) while starting it from signal stops or stop signs....the rpm drops suddenly, hence loss of power and then comes back up to normal....this happens when I have gentle push on the paddle....when give it hard push it does not happen....now this starting happening when I flushed the transmission fluid....but then I got the emissions parts also changed at the same time under the MB emissions campaign after the law suit....so not sure what it is the actual cause of it....no check engine light no warning...
Also, the transmission flush had to be done as I had changed the transmission fluid a month ago but I used the red one instead of blue one which was recommended for my car so had to flush the old one out....but even with wrong fluid the loss of power was not there....so I am inclined towards emissions parts being the cause of it????? Please share if anyone has nailed it down...

cadetdrivr

Where are you located?

If you are in the USA there is currently a recall where MB will replace virtually the entire exhaust/emissions system, reprogram the ECU. and provide a new warranty,

notorius

My bad luck i am in Canada

notorius

we do have same law suite here as well but no decision yet

excal

I have the same issue on my ML Bluetec. The issue happens from a stop or after coasting, if I very lightly press the accelerator say 10% and hold it there, the engine will miss, stutter and surge until I press harder and then acceleration is fine.

I suspect it's a sticky EGR valve but haven't had a chance to remove it and check. No codes are showing (yet)

notorius

yes same issue here.

notorius

ok i cleaned the EGR and now i am 90% sure it was EGR

excal

Good to know. Was the EGR hard to remove?

notorius

Very hard, and putting back as well, my knees still hurt from all standing in weird position and hands are all scratched because of weird positioning.

excal

Thanks. Not looking forward to it. Was it physically stuck? Searching around I've read about various methods from the flange with a chisel to loosening the bolts and going for a spirited drive. What method worked for you?

notorius

it was physically stuck had to chisel it out. i would recommend doing it right way if you seeing symptoms else the part is expensive if it overheats and fails. it is out of stock too. i heard wait times could be months

rosswell

Well I was going to start this thread but I see it already exists so here is my experience in Canada from today. At low velocity (like slowly driving through a subdivision looking at the houses) it's impossible to modulate the throttle smoothly without the surging and bucking (like in a gasoline engine car that is missing on more than a couple cylinders). The MB Tech described it as slight jerking when lightly accelerating at low speeds or with cruise engaged at about 50 km/h. It runs fine at highway speeds or full throttle. I just got my GL 350 back from M.B. service (which was $800 bucks for a compression test (Which only showed compression was fine at 21-22 bar). They say they found some faults for exhaust temp sensors and back pressure sensor. They did some software updates for the CDI and transmission control unit. They inspected the engine control unit and cleaned a corroded pin for injector #2. They checked back pressure sensor and temp sensor and mass air flow sensors which were within spec. They did gear shift adaptations (since the lockup clutch slips before shifting at very light throttle when this fault happens) and speculated that the vibration occurs when the lockup clutch slips during gear changes which may not be normal. After driving back home on the highway it still does what it always does (the chugging at low constant throttle). I'm happy to have any advice up to and including paying someone to remove all of the AdBlue and emissions crap if that's a fix. Happy to have any thoughts people thanks. This has been a gradually worsening problem starting out only when backing down the driveway and changing direction. I've also noticed amazing fuel mileage as possibly related.

notorius

i can see what you are saying is its related to emissions hence high fuel efficiency. thats why cleaning EGR valve solved the problem temporarily and then its back now. But when you got troubleshooting from MB dealer they should have found the issue. as for fault code, they should have shown as engine light. if there was no engine code then probably its made up goof ?. i just wish we get resolution of bluetec case in canada soon. Where about are you located ?

rosswell

I had no engine light and the codes were deeper ones. Western Canada (AB). I use the north dealer. Oddly the engine runs perfectly when cool but at temperature the low velocity surging returns.

notorius

same here, car fine when cold but issue when hot. I tried OBD scanner and could not find any codes either along with no engine light. I am in BC.
so i understand your problem is still there after visit to MB dealership. I am looking into local shops that does EGR/DEF/DPF delete

BlownV8

From what I understand, the diesel lawsuit is being rolled out to Canada. You will lose out on a heck of an extended warranty from MB if you do any modifications.

notorius

i know about that, in US they are already making payments + warranty + change of components. there is no updates on what is happening in canada. i even tried calling the law firm based in toronto. if you have any recent info that would be great.

notorius

https://kmlaw.ca/cases/mercedes-bluetec-class-action/

berlinbai

I was just about to start a thread and saw this.
I've noticed this stutter as well, fuel economy is amazing as always 7.2./100km on hwy
My 2013 ML350BT had the NOx sensors changed once before by stealer $2000, Soot sensor change under warranty.

Has anyone thought about checked the air filter condition?
I mean if under light throttle/after coasting/after stopping, the turbo isn't spinning very fast, and we apply say 10%throttle to demand certain amount of air and fuel, our fuel injection is pretty precise on fuel, but if the air filter is somewhat dirty plus the turbo isn't spinning fast, it would cause mixture too rich. and thus poor performance for a few sec until turbo catches up, or the ecu to adjust since our modern diesel do have a throttle which is control by the ecu.
Thoughts? I don't know if all this makes sense, someone with the knowledge please educate me. But I'm desperate to change my fuel fitler, and air filter and clean EGR valve TOMORROW, I'll post back the result.

cheers

PS, if none of this helps the situation and the car does nothing else and shows no engine light or codes, I would just wait out on the class action.

captivabenz

Exchange of components and software updates, but as far as I am aware, no payments have been reported..

notorius

I would suggest doing 1 part at a time and test to find out what solved the issue

for me my air filters are clean (atleast from the looks)
fuel filter i have changed it already and when the problem came back, i put older one back. i had it lying around.

Then in the end touch the EGR and its most time consuming and hardest to deal with

notorius

sorry are you talking about canadian law suite or US. Nothing has happened in Canada. US had components changed and warranty given out