Diagnostic question on 2008 ML320 CDI
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Joined: Jan 2011
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ML320 CDI
Diagnostic question on 2008 ML320 CDI
Hoping this the right location to post?
A search found nothing that was a 100% hit.
Issue: does not accelerate aggressively.
Car: 2008 ML320 CDI 124,000 km.
Environment: cold outdoors -15 to -20 C. (0 F)
Nb the previous week, when it was colder issue was not present.
This is a brand new issue.
I did not notice the problem initially, when accelerating smoothly and non aggressively to highway speeds 120kmph (70 mph).
If I then floor it, almost nothing happens, it's as if I only slightly depress the accelerator (but its floored) and it very slowly accelerates.
From start it accelerates briskly initially but quickly tops out.
Again as if I'm not pressing hard on the accelerator, any longer.
And goes through the gears in a quick progressive manner.
In neutral and floored it revs quickly to 3000 rpm and no further
I do notice a clunk and small lunge in the tranny just before a stop, but there was always a small one, seems a bit worse however.
Starts fine, no hesitation during the limited acceleration, ie its smooth.
My thoughts
- if it were bad fuel, the initial acceleration would also be jittery... It's not
- if it was a blown tubo gasket, I would not get to 130-140 kmph
- if it was a tranny issue, It would not completely ignore and not react to being floored.
I'm stumped any ideas before my Dealer visit?
Thanks in advanced for your feedback & my education.
PAP
A search found nothing that was a 100% hit.
Issue: does not accelerate aggressively.
Car: 2008 ML320 CDI 124,000 km.
Environment: cold outdoors -15 to -20 C. (0 F)
Nb the previous week, when it was colder issue was not present.
This is a brand new issue.
I did not notice the problem initially, when accelerating smoothly and non aggressively to highway speeds 120kmph (70 mph).
If I then floor it, almost nothing happens, it's as if I only slightly depress the accelerator (but its floored) and it very slowly accelerates.
From start it accelerates briskly initially but quickly tops out.
Again as if I'm not pressing hard on the accelerator, any longer.
And goes through the gears in a quick progressive manner.
In neutral and floored it revs quickly to 3000 rpm and no further
I do notice a clunk and small lunge in the tranny just before a stop, but there was always a small one, seems a bit worse however.
Starts fine, no hesitation during the limited acceleration, ie its smooth.
My thoughts
- if it were bad fuel, the initial acceleration would also be jittery... It's not
- if it was a blown tubo gasket, I would not get to 130-140 kmph
- if it was a tranny issue, It would not completely ignore and not react to being floored.
I'm stumped any ideas before my Dealer visit?
Thanks in advanced for your feedback & my education.
PAP
Last edited by Papcan514; Jan 26, 2013 at 12:12 PM.
Member
Joined: Apr 2008
Posts: 205
Likes: 21
From: Florida & North Carolina
2008 ML320CDI 4Matic, 2006 C350
Could indeed be the initial symptoms of the known transmission issue.
See my experience:
https://mbworld.org/forums/m-class-w...ion-issue.html
See my experience:
https://mbworld.org/forums/m-class-w...ion-issue.html
Newbie
Joined: Feb 2013
Posts: 1
Likes: 0
2008 ML320 CDI
I have the same issue... same exact year and model with 81K miles. Also, same cold weather conditions.
I will press the gas pedal as far down as possible and it wont accelerate past 40 MPH.
Have you taken it to the dealership yet? any luck figuring out exactly what it waS?
I will press the gas pedal as far down as possible and it wont accelerate past 40 MPH.
Have you taken it to the dealership yet? any luck figuring out exactly what it waS?
Senior Member
Joined: Feb 2010
Posts: 431
Likes: 4
From: Cross Roads, PA
2008 ML320CDI
Its an EGR issue, it puts the vehicle in limp mode. It will go away after car reaches temp and you turn off wait 5 min and start again. First time it happened to me I got a Check Engine light, the last time it did not post any errors.
Member
Joined: Dec 2011
Posts: 144
Likes: 10
2008 R320 CDI, 2006 smart fortwo cabrio, 1983 240D, 1982 300SD, 1980 300SD
You have a minor limp mode of some sort or partially gelled fuel and it is starving. You must have it scanned for codes with a star reader (Mercedes oem code reader) to extract all the codes and go from there. It could many different things, engine, transmission, fuel etc. Lots of issues can cause these limp modes.
