2008 CLS - Jerky gearbox on kickdown

[DaveTheRave]

Hello!

I am new to both Mercedes cars and the forum!

Having owned my CLS 320CDI (2008) now for nearly a year and have just gone over 110k miles it's been a great car.
Now I have an issue where the gearbox (I think) when coming out of a junction and you need to boot it, when the car attempts a kickdown it just jerks as if it's trying to change gear but doesn't do anything apart from the car shaking or as if it's jumping if that makes sense, until I lift off the pedal and then it's fine, I can kick down again and it will work but just when coming out of a junction it does this, not all the time but more noticeable lately especially at lower speeds not had it when actually moving above say 20mph. No warning on the dash or anything, don't have a code reader currently to see if it's stored any codes but does anyone have any experience with this issue. The car had it's gearbox service around 6 months ago when it was at around 100k but been fine until now.

Any help would be appreciated. Cheers.

 

[W1ghty]

Hello!

I am new to both Mercedes cars and the forum!

Having owned my CLS 320CDI (2008) now for nearly a year and have just gone over 110k miles it's been a great car.
Now I have an issue where the gearbox (I think) when coming out of a junction and you need to boot it, when the car attempts a kickdown it just jerks as if it's trying to change gear but doesn't do anything apart from the car shaking or as if it's jumping if that makes sense, until I lift off the pedal and then it's fine, I can kick down again and it will work but just when coming out of a junction it does this, not all the time but more noticeable lately especially at lower speeds not had it when actually moving above say 20mph. No warning on the dash or anything, don't have a code reader currently to see if it's stored any codes but does anyone have any experience with this issue. The car had it's gearbox service around 6 months ago when it was at around 100k but been fine until now.

Any help would be appreciated. Cheers.

This jerking has been an issue in the past with the om642 engine , it could be a turbo actuator fault , but either way a diagnostic with a Mercedes specific reader like icarsoft or MB Star diagnostics will show the reason even though there is no dash light

 

[DaveTheRave]

This jerking has been an issue in the past with the om642 engine , it could be a turbo actuator fault , but either way a diagnostic with a Mercedes specific reader like icarsoft or MB Star diagnostics will show the reason even though there is no dash light

Thanks for the reply! Just ordered an icarsoft CR V2.0 so hopefully I will know what the issue is and nothing too serious. Will update on the findings, thanks again

 

[Larkone]

If it is a the turbo actuator - probably needs a strip, clean and lube or a refurb unit - then it doesn't show codes. Had the same kangarooing with mine and a strip, clean and lube sorted it.

 

[W1ghty]

Thanks for the reply! Just ordered an icarsoft CR V2.0 so hopefully I will know what the issue is and nothing too serious. Will update on the findings, thanks again

Good stuff , let us know how you get on buddy

 

[DaveTheRave]

Sorry for the long delay, first scanner had a broken screen so had to wait for a replacement.

So having scanned the car I had 3 current errors showing and a couple historic ones. 1 for Parktronic system dirty sensor I presume.
The other 2 are
2038-2 - Check Component 02 Sensor upstream of KAT, Resistance too small.
2030-4 - Check Component O2 Sensor upstream of KAT, Open Circuit

The historic ones are Glow plus on cyl 1 & 4 but fires up and warms up fine every morning so I am not worried about that.
The other historic ones is 2510-1 Check component Y77/1(Boost Pressure regulator), Position signals fault.

Now I am not massively knowledgeable on cars/engines and so on but surely the O2 sensors would not be causing this issue, I am more worried about the historic boost pressure regulator code.

What do you guys think?

Thanks.

 

[Larkone]

It is highly likely the o2 sensor has gone, only one, easy to get to and not expensive. These engines seem to eat them as part if their diet.