E350 jerking at low revs
06-06-2021, 02:50 PM
#1
E350 jerking at low revs
Hi, I've got a 2011 e350 w212 3liter v6, with the 7g+ gearbox when the coolant temp is below 50° and revs are between 1000 and 2000rpm the car acts like it's going to cut out and jerks until you get above 2000rpm in 1st 2nd and 3rd gear then drives fine with no fault codes.
The issue started after i carried out a gearbox oil change, the transmission fluid that was supplied was the red 236.14 after checking twice i was told it was the right oil, after the issues started and contacting merc it turned out it was the wrong oil it should of been 236.15 (blue) car was driven approx 80 miles with the wrong oil in.I've since drained the wrong oil from the gearbox,drained torque converter and flushed the cooler through changed the filter and refilled with approx 8.5liter (out of 9 liters from merc after running it up to 45° ECT,(gearbox temp) I also did a engine oil, fuel filter,Air filter and diff oil change(all air intake seals were replaced) at the same time as the original transmission oil change.
has anyone experienced this before am I barking up the wrong tree looking for a gearbox fault?
any help, advise kick in the right direction welcome
thank you stu
The issue started after i carried out a gearbox oil change, the transmission fluid that was supplied was the red 236.14 after checking twice i was told it was the right oil, after the issues started and contacting merc it turned out it was the wrong oil it should of been 236.15 (blue) car was driven approx 80 miles with the wrong oil in.I've since drained the wrong oil from the gearbox,drained torque converter and flushed the cooler through changed the filter and refilled with approx 8.5liter (out of 9 liters from merc after running it up to 45° ECT,(gearbox temp) I also did a engine oil, fuel filter,Air filter and diff oil change(all air intake seals were replaced) at the same time as the original transmission oil change.
has anyone experienced this before am I barking up the wrong tree looking for a gearbox fault?
any help, advise kick in the right direction welcome
thank you stu
06-06-2021, 10:03 PM
#2
Out Of Control!!
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2017 GLE350 4MATIC
To state the obvious, it sounds transmission related. Wrong fluid is not a good first step. Posts on this site suggest 3 drains/refills to purge fluid contamination (wrong fluid).
On the other hand/in addition, how many miles are on this vehicle? It could also be a failing torque converter (lockup clutch) or the electrohydraulic unit (conductor plate).
The least expensive path forward is probably 2 additional fluid flushes. Then see what happens and report back here.
On the other hand/in addition, how many miles are on this vehicle? It could also be a failing torque converter (lockup clutch) or the electrohydraulic unit (conductor plate).
The least expensive path forward is probably 2 additional fluid flushes. Then see what happens and report back here.
The following 2 users liked this post by chassis:
CaliBenzDriver (06-07-2021),
pierrejoliat (06-06-2021)
06-07-2021, 12:30 AM
#3
Thank you for the reply the car has done 81,000 miles.
Do you think it could just be a coincidence that's it's acting up or would the wrong fluid take out the torque converter? Cheers
Do you think it could just be a coincidence that's it's acting up or would the wrong fluid take out the torque converter? Cheers
06-07-2021, 02:41 AM
#4
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MY'14 W212 M276 3.5NA @60kMi
the process of elimination dictates to go to the obvious first... flush your ATF and drain the converter to help along.
At some point, consider a TCM reset to make it forget running the wrong fluid viscosity.
Do you know for sure this low rpm problem did not predate the transmission mess... ie. is it not engine related for sure... You replacing intake seals could have introduced air leak: lean misfire??
At some point, consider a TCM reset to make it forget running the wrong fluid viscosity.
Do you know for sure this low rpm problem did not predate the transmission mess... ie. is it not engine related for sure... You replacing intake seals could have introduced air leak: lean misfire??
Last edited by CaliBenzDriver; 06-07-2021 at 03:11 AM.
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Stu_22 (06-10-2021)
06-07-2021, 08:39 AM
#5
MBWorld Fanatic!
The symptoms sound more engine related to me, like a vacuum leak. As engine revs increase the engine overcomes the extra air (lean at idle/low rpm) and smooths out.
To verify, use a scantool to look at short term fuel trim on both banks. Should be as close to 0 as possible but can range 5% or so, to positive or negative.
If STFT is staying at higher positive at idle and low rpm, that means the ECU is adding fuel. If the STFT goes back into normal range as revs increase that's usually an indicator of a vacuum leak. You will usually also see LTFT tending to positive to indicate the ECU long term strategy of adding more than usual fuel to compensate for lean condition such as with a vacuum leak.
Intake seals could be an issue as they can easily get shifted during installation. But don't overlook simple stuff like a hose or the air filter housing not being seated properly at the MAF housing rubber gasket. You can also use a scantool to verify if there are actually any intermittent misfires as they don't always throw the CEL.
You're in the spot of needing to verify all of the work you did so I suggest not just focusing on transmission.
To verify, use a scantool to look at short term fuel trim on both banks. Should be as close to 0 as possible but can range 5% or so, to positive or negative.
If STFT is staying at higher positive at idle and low rpm, that means the ECU is adding fuel. If the STFT goes back into normal range as revs increase that's usually an indicator of a vacuum leak. You will usually also see LTFT tending to positive to indicate the ECU long term strategy of adding more than usual fuel to compensate for lean condition such as with a vacuum leak.
Intake seals could be an issue as they can easily get shifted during installation. But don't overlook simple stuff like a hose or the air filter housing not being seated properly at the MAF housing rubber gasket. You can also use a scantool to verify if there are actually any intermittent misfires as they don't always throw the CEL.
You're in the spot of needing to verify all of the work you did so I suggest not just focusing on transmission.
The following 2 users liked this post by Mud:
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06-07-2021, 01:50 PM
#6
Senior Member
I think I'm with Mud on this one. Probably engine related, not accelerating smoothly when cold but smooths out when warmed up. This will be interesting.
Last edited by Sunnyslope48; 06-07-2021 at 01:54 PM.
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Stu_22 (06-10-2021)
06-10-2021, 03:15 PM
#7
Hi sorry for the late reply,
so after convincing myself it was a gearbox issue it turned out it wasn't I had to fetch my caravan from storage and when I was pulling it there was an obvious vacuum leak so went to mb and ordered new seals (again)for the air intake and turbo charge pipe removed the air intake pipe and saw the charge pipe not sat in place properly on closer inspection i found the threads had gone for the bracket on the charge pipe allowing it to move back slightly and creating a leak.
replaced the seals and re-tapped the threads rebuilt it and road tested it and so far it's been ok for 2 days. Thank you everyone for your help.
so after convincing myself it was a gearbox issue it turned out it wasn't I had to fetch my caravan from storage and when I was pulling it there was an obvious vacuum leak so went to mb and ordered new seals (again)for the air intake and turbo charge pipe removed the air intake pipe and saw the charge pipe not sat in place properly on closer inspection i found the threads had gone for the bracket on the charge pipe allowing it to move back slightly and creating a leak.
replaced the seals and re-tapped the threads rebuilt it and road tested it and so far it's been ok for 2 days. Thank you everyone for your help.
The following users liked this post:
CaliBenzDriver (06-10-2021)
