Acceleration Judder from under the car (More noticeable at high speeds)
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Mercedes C350 W204
Acceleration Judder from under the car (More noticeable at high speeds)
Hello,
I have a W204 350CDI 7G 4matic estate. It has this vibration thats been there since i bought the car in 2021. It seems to be a transmission problem as i can feel the vibration from underneath from both the front of the vehicle and the back and the vibration radiates from back to forth when accelerating on the motorway. Many parts have been changed in trying to eliminate this vibration; - Propshaft, flex discs, both front driveshafts, differencial bearing, gearbox service and still the vibration persists! I have spent 2000€ in trying to sort this problem out. Does anyone have a clue what it could be??? Please, any help would be massively massively appreciated.
I would also like to note that there are a few other things wrong with the car which i beleive are not related to the vibration issue (but who knows?). On a cold start, when i put the car in reverse, it stalls or if it doesnt stall, it idles rough until warm. It also idles rough when put into drive but it has yet to stall in D. If the car is warm, this problem doesnt happen.
Currently, i have the ABS, ESP and traction lights on at the moment, i have been told that this is a common fault and a module has to be changed for the lights to go out on the dash. Could someone confirm me this?
The vibration issue is what really needs to be sorted here as i am going to sell the car and wont be able to sell it with these faults.
Again, any help on this matter would be massively appreciated.
I have a W204 350CDI 7G 4matic estate. It has this vibration thats been there since i bought the car in 2021. It seems to be a transmission problem as i can feel the vibration from underneath from both the front of the vehicle and the back and the vibration radiates from back to forth when accelerating on the motorway. Many parts have been changed in trying to eliminate this vibration; - Propshaft, flex discs, both front driveshafts, differencial bearing, gearbox service and still the vibration persists! I have spent 2000€ in trying to sort this problem out. Does anyone have a clue what it could be??? Please, any help would be massively massively appreciated.
I would also like to note that there are a few other things wrong with the car which i beleive are not related to the vibration issue (but who knows?). On a cold start, when i put the car in reverse, it stalls or if it doesnt stall, it idles rough until warm. It also idles rough when put into drive but it has yet to stall in D. If the car is warm, this problem doesnt happen.
Currently, i have the ABS, ESP and traction lights on at the moment, i have been told that this is a common fault and a module has to be changed for the lights to go out on the dash. Could someone confirm me this?
The vibration issue is what really needs to be sorted here as i am going to sell the car and wont be able to sell it with these faults.
Again, any help on this matter would be massively appreciated.
Thread Starter
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Joined: Dec 2021
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Mercedes C350 W204
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Joined: Sep 2013
Posts: 2,346
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
That is correct. The transmission mount is quite easy. The 2 engine mounts are hard to do on the V engines with 4 Matic. It doesn’t take any special tools, just a lift to hold up the engine so they can be accessed.
I we would suggest using Mercedes mounts but an independent MB or German car shop for lower labor rates.
I we would suggest using Mercedes mounts but an independent MB or German car shop for lower labor rates.
Thread Starter
Newbie
Joined: Dec 2021
Posts: 7
Likes: 0
Mercedes C350 W204
That is correct. The transmission mount is quite easy. The 2 engine mounts are hard to do on the V engines with 4 Matic. It doesn’t take any special tools, just a lift to hold up the engine so they can be accessed.
I we would suggest using Mercedes mounts but an independent MB or German car shop for lower labor rates.
I we would suggest using Mercedes mounts but an independent MB or German car shop for lower labor rates.
Many thanks for the advice much appreciated! 👍🏻👍🏻
MBWorld Fanatic!
Joined: Sep 2013
Posts: 2,346
Likes: 692
2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
At 100,000 miles new mounts gave my C250 that new car feel again. Let’s hope this does it for you.
Then you can address the other 2 issues.
I would go for the ESP, ABS, TC lights next. Those are safety systems. It is common and most often related to the wheel speed sensors. It might be as simple as a broken wire to one of the sensors, or a bad sensor, or even a badly corroded reluctor ring on a wheel. Maybe a bad module, but often not.
Then the rough cold start. As cars age, things that have diaphragms, valves, orifices don’t work as well as they once did. For about the first 2 minutes the engine is running on defaults (open loop), the ECU isn’t making any adjustments, and all that needs to be perfect. If it’s running well after warm up, something like the EGR valve, crankcase vent valve, or evaporative purge valve could be at fault. It may show some stored codes but maybe not as the ECU isn’t looking for problems until the engine goes to “closed loop.” Just needs someone to get under the hood and check. If you can let the engine idle for 30 seconds (no more than 2 minutes) before driving off, it may remove some of the unpleasantness.
Then you can address the other 2 issues.
I would go for the ESP, ABS, TC lights next. Those are safety systems. It is common and most often related to the wheel speed sensors. It might be as simple as a broken wire to one of the sensors, or a bad sensor, or even a badly corroded reluctor ring on a wheel. Maybe a bad module, but often not.
Then the rough cold start. As cars age, things that have diaphragms, valves, orifices don’t work as well as they once did. For about the first 2 minutes the engine is running on defaults (open loop), the ECU isn’t making any adjustments, and all that needs to be perfect. If it’s running well after warm up, something like the EGR valve, crankcase vent valve, or evaporative purge valve could be at fault. It may show some stored codes but maybe not as the ECU isn’t looking for problems until the engine goes to “closed loop.” Just needs someone to get under the hood and check. If you can let the engine idle for 30 seconds (no more than 2 minutes) before driving off, it may remove some of the unpleasantness.
