W204 C200K RPM drop and jerk.

[rafi1407]

Hello,

My C200K has been driving me nuts. The car has around 43800 Km. It has been recently serviced in the dealer. Chassis number is WDD2040411F054615, which I have already decoded here: Vin Check. I have had two independent mechanics try to pinpoint the cause to no avail.

The issue is that, when light on the throttle and at around 20 km/h, the rpm drop and I can feel the car jerk enough to be uncomfortable, now imagine this happening 100 times on slow stop and go traffic. This happens regardless of gear, as I can hold 1st gear in manual mode and it still does it, so it's not the transmission shifting. When I go full throttle, it doesn't happen or it's barely noticeable. There are no visible transmission leaks, or any leaks for that matter. The car is equipped with the 5 speed transmission I believe to be the 722.6. There are no error codes or lights anywhere, stored or current. It does it in all transmission modes (c, s and m).

Here is a video of the occurrence:

https://www.youtube.com/watch?v=sJysN2yloqM

I hope you guys can point me in the right direction, thanks.
​

 

[mbenz1]

Has the car been checked on a STAR diagnostic code reader machine or a normal/compatible code reader? If not, then its worth getting it checked on a STAR. Normal code readers may not show up everything... 43,000 km is roughly 27,000 miles so engine has significantly low miles...

Guys, could this be a MAF issue by any chance?

 

[rafi1407]

Has the car been checked on a STAR diagnostic code reader machine or a normal/compatible code reader? If not, then its worth getting it checked on a STAR. Normal code readers may not show up everything... 43,000 km is roughly 27,000 miles so engine has significantly low miles...

Guys, could this be a MAF issue by any chance?

First of all, thanks for your response.

Unfortunately the car has been checked with the dealer computer (for a quick check during maintenance) and nothing showed up, no stored codes. Two subsequent "quick checks" have been made with those IBM laptops and official MB software and hardware (Xentry I believe).

Should I get someone to supervise live values on the car when the problem occurs? What should I be looking for?. This is really strange, the car idles perfectly and gearshifts are smooth, but this jerk keeps coming on at around 20 and 30 Km/h, regardless of gear, and when in slow or constant acceleration.

 

[mbenz1]

First of all, thanks for your response.

Unfortunately the car has been checked with the dealer computer (for a quick check during maintenance) and nothing showed up, no stored codes. Two subsequent "quick checks" have been made with those IBM laptops and official MB software and hardware (Xentry I believe).

Should I get someone to supervise live values on the car when the problem occurs? What should I be looking for?. This is really strange, the car idles perfectly and gearshifts are smooth, but this jerk keeps coming on at around 20 and 30 Km/h, regardless of gear, and when in slow or constant acceleration.

I'm not an engine expert but I have learnt in this forum that live engine data using a STAR diagnostic code reader machine at any MB specialist/independant or MB dealer may lead to more specific diagnosis and help in finding out what the problem is. Hopefully our experieneced forum members can help you out here...

If this problem has occurred immediately or fairly quickly after getting the car serviced by the dealer then is it worth chasing them up and giving them the blame??? What was done in the service?

 

[lsdlsd]

Hi rafi,

From what I understand based on your description I would say nothing is related to the engine with those symptoms!

I have a W203 C180K with same engine as yours M271 Petrol engine and 722.695 Automatic transmission. I have similar symptoms and the strange thing here is that when the car gets fully warmed up, when driving at low speeds mainly heavy traffic roads (drive - stop - drive - stop) the vibration when braking to full stop is very noticeable.

https://www.youtube.com/watch?v=CNvyCRm712U&list=UUx8dBYclabhiub3wmgOc1wg

Until now, I've done the following tests (hope these will help you not to waste time and money on useless tries):

1. Tests with parts in order to find out the problem
- Tested with different same PN MAF
- Tested with different Throttle Body (same PN)
- Tested with different vacuum pum

2. Repaired problems that would cause the issue.
- Repaired every air leak in the intake manifold and supercharger contact assemblies.
- Replaced defective air pipe under air filter case (MB is aware of the following - TSB released)
- Changed Ignition Sparks
- Changed Torque converter
- Changed one of the ignition coils that had signs of poor efficiency (better engine idle after change).

3. Calibrations / Live Tests (using MB DAS Xentry).
- Learn engine rpm without / with gear engaged
- Learn throttle body position.
- Re-calibration of shifting times.
- Monitored engine air pressure / air intake volume / ignition system.
- Torque converter lockup (disablement) - for testing reasons.

From the above actions nothing seemed to make any difference on fixing the problem. One thing I noticed during the monitoring with MB computer was the intake air temperature that at idle was around 55+ degrees Celsius where the acceptable temperature was equal or less than 35 degrees Celsius.

All left now in my doubts is the automatic transmission itself (excluding the torque converter) to have the problem.

Same symptoms, no error codes, nothing at all telling where the problem is.

Hope you have found anything related to that until now!

Regards, Lsd

 

[teekay]

My 2007 w204 C200k does exactly the same thing, however its much more noticeable in sport mode than comfort mode, which makes me believe it must be software related? Please keep us updated...

 

[gs63]

First place I would be looking is for air leaks, I am sure they are very common on these. There is a vacuum pipe that usually goes soft and splits right in front of Kompressor unit just under throttle body.

This is if I am thinking of the same engine

 

[weidnerd]

Even without them splitting, I have accidentally disconnected air lines when changing the oil filter before, and had the same symptoms. Look for translucent hard plastic tubes - they just push-fit into black rubber connectors. One of those could have escaped - then it messes with the air pressure values at the MAF, and hence screws up your fuel/air mix!

 

[shadyali]

i fixed the vacuum and changed almost all air tubes... and still dealing with the same problem... and no signs of errors on the STAR.

 

[shadyali]

last thing i made that slightly fixed the problem was changing the transmission's oil.. now sometimes it makes the problem and sometimes it just drive smooth so i dont know wether the gearbox is healing it's self of the problem is still there ummm i donno

 

[Rk91]

Hello,

Has anyone found a soloution to this problem my 2008 c200 cdi sport has the same issue and it is really annoying in heavy traffic

 

[Razahrani]

Hello,
I have the same exact symptoms in my w204 (C200 2012). Should we really anticipate a problem within the transmission? In fact, given my field of work where I deal with industrial combustion applications, I can be quite sure that the problem is with bad fuel/air mixtures at low control element opening (low throttle). This is supported by the following two facts:
1. BlueEfficiency Engines are known for their extreme fuel efficiency which means Fuel Injectors should be smaller at nozzles in order to get optimised flow. This could in turn make the Injectors more prone to fouling and thus bad mixtures. Six months ago I had the same jerking issue, and a technican (25+ yrs exlerience) suggested to shock dose the injection system with three bottles of cleaners (Liquimoly). Things went perfect afterwards. Now the problem is back, I did the same now but the problem is still there.
2. Same above rationale applies with the air injection system. Couple of months ago, I had another similar problem of reduced efficiency and black smoke at cold morning start up. Then diagnosis showed oil leak in the turbo where oil gets mixed with air. Leak was stopped and engine went back smooth.
Now I am going to get air tightness check. Until then, I hope we can hear from others with their experience on this problem.
Regards

 

[190]

My C180K BE with manual transmission also has a slight hesitation but only at very slow speed and only really noticeable when pulling away in 1st gear.

It might be a fault but the cynic in me thinks it might even have being deliberately programmed into the "fly by wire" response to counter clumsy application of the throttle. For whatever reason it isn't noticeable in 2nd gear and with 1st being too low a ratio anyway, short of hill starts I routinely pull away in 2nd which believe it or not is actually what is recommended in the owners manual.

 

[chico1886]

hey everyone

having same problem on my 2008 c200k. Seems to be happening after car is run a while especially if in traffic for a while. cold starts are terrible, the gearbox jerks hardest and really struggles to move.

really need help with this

Thanks all in advance

 

[chico1886]

hey. any luck with this issue?

 

[lsdlsd]

Hi guys,

I would like to add some updates to this thread.

The symptoms seem to disappear when on the same engine and automatic transmission you test a preconfigured different ECU which has manual transmission configuration. (Simply swap it from a manual transmission car if you find for test)

Stressed the car on different traffic conditions and hot weather without any jerk or rpm fall as used to happen previously.

In this scenario i guess transmission and engine are operating independently ignoring information exchange.
Based on this, the issue has nothing to do with any of the suspected causes like oil, air system, maf, cam sensors or any other component.

On my long way to find a solution to this problem I've managed to change almost everything including full transmission reconditioning, ecu change but no luck!

All I'm left my doubts on is the ecu firmware which is not able to coordinate with transmission signals causing this symptoms.

If any of you has a clear picture on what is the information exchanged between engine and transmission (schematic) in order to trace the problem it could be helpful.

Looking forward for further feedback...

Br, LSD

 

[lsdlsd]

Hi guys,

I would like to add some updates to this thread.

The symptoms seem to disappear when on the same engine and automatic transmission you test a preconfigured different ECU which has manual transmission configuration. (Simply swap it from a manual transmission car if you find for test)

Stressed the car on different traffic conditions and hot weather without any jerk or rpm fall as used to happen previously.

In this scenario i guess transmission and engine are operating independently ignoring information exchange.
Based on this, the issue has nothing to do with any of the suspected causes like oil, air system, maf, cam sensors or any other component.

On my long way to find a solution to this problem I've managed to change almost everything including full transmission reconditioning, ecu change but no luck!

All I'm left my doubts on is the ecu firmware which is not able to coordinate with transmission signals causing this symptoms.

If any of you has a clear picture on what is the information exchanged between engine and transmission (schematic) in order to trace the problem it could be helpful.

Looking forward for further feedback...

Br, LSD

 

[Jair]

"One thing I noticed during the monitoring with MB computer was the intake air temperature that at idle was around 55+ degrees Celsius where the acceptable temperature was equal or less than 35 degrees Celsius."

My W204 C200K 2008 doesn't show up any strange behavior, works like a charm.
New sparks, all checked and cleaned up.

But annoying CEL light always on, P2187 error at standard scanner, only strange parameter - temperature at idle around 38 degrees Celsius - a bit over 35 - using Xentry.
Air temp sensor cleaned and changed for another later, no luck.
So the sensor says it hot because it is hot.

What is the place/part that makes the air hotter than ambient ? Inside compressor ?

PS: In the past I had to fix that two magnets which controls valves motion, because of oil leak - this is a well know problem for this car - after I fixed car used to turn off in the middle of traffic.

 

[190]

The slight hesitation I mentioned in post #13 has gone away on it's own. Totally convinced it was software related and that's on a manual.

When you press the throttle on a modern car it's just changing an input to the ECU so throttle response is totally dependant on the software.

 

[Kush1812]

Hello,

My C200K has been driving me nuts. The car has around 43800 Km. It has been recently serviced in the dealer. Chassis number is WDD2040411F054615, which I have already decoded here: Vin Check. I have had two independent mechanics try to pinpoint the cause to no avail.

The issue is that, when light on the throttle and at around 20 km/h, the rpm drop and I can feel the car jerk enough to be uncomfortable, now imagine this happening 100 times on slow stop and go traffic. This happens regardless of gear, as I can hold 1st gear in manual mode and it still does it, so it's not the transmission shifting. When I go full throttle, it doesn't happen or it's barely noticeable. There are no visible transmission leaks, or any leaks for that matter. The car is equipped with the 5 speed transmission I believe to be the 722.6. There are no error codes or lights anywhere, stored or current. It does it in all transmission modes (c, s and m).

Here is a video of the occurrence:

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I hope you guys can point me in the right direction, thanks.
​

Hello, recently 3 days back I started to face the same issue. The car was running perfect before I decided to get the Throttle Body and the Injectors cleaned. I replaced the Ignition coils, Spark Plugs. The fuel pumps were replaced a month back. Could you find any solution to ur problem?