Sometimes when I come to a stop I feel a clunk like someone just rear ended me. It doesn't do this all the time though, mostly in sport mode, not in comfort or sport+. Is this normal? It doesn't feel normal and I'm going to mention it when I take it in for service next time.

 

Does it happen with each stop? I hear a light click roughly after a minute of driving (after starting the car) when I come to a full stop (to make a right turn), and this happens exactly at the same location each time. At least for this case, I think it's the ABS resetting/calibrating

It happens only the very first time I come to a full stop, but doesn't happen after that.

 

Sounds like the transmission doing a rough/hard down-shift. In my experience (2017 C43 and 2016 C63 S), that's more likely to occur when the transmission is not yet warmed up. It's also very likely to occur just after a transmission controller has been reset (or "adapted") and is in more of a learning/adaptation mode.

Finally, I find that such "clunky" shifts will intermittently occur, regardless of any of the above. I've found that to be true for all Mercedes (AMG and non-AMG) having a "planetary gear" type transmission (for me that started with a 2007 model-year E-series).

In my C63 S, which has a wet clutch (as opposed to a torque converter) sometimes those hard down-shifts are so severe that they trigger my dashcam's collision-activated recording (but so does slamming a door). Unless you're constantly experiencing this, I wouldn't worry about it.

 

I mentioned it when I took it in for the 20k service and they updated the software that controls the transmission and it works fine now. I also mentioned there was some flaking of the metallic finish on the convertible top switch so they replaced that as well.

Man, this car takes 9.5 quarts of motor oil too!

 

Almost every stop it happens. The dealership was able to confirm the problem and a software update it seems to have fixed it. I drove it home and to work this morning in Sport mode and didn't experience the problem at all. It would have happened over and over again prior. Warm/cold it didn't matter. It did it constantly.

I bought the car CPO with 16k miles on it. I imagine the previous owner just drove it in comfort mode all the time because this was really annoying. It's not a clicking, it feels like someone rear ended you after you come to a stop. Like the clutch is matching up to speed of the flywheel and it is very abrupt.

 

I have been trying to resolve this exact issue on my car for few months now. Now I’m wondering if mine is related to this. Was it really just a software update? What type of software update exactly?

I have never messed with TCU updates/software/etc… I just don’t know what to replace anymore.

I would love to hear some modern feedback from everyone.

(My apologies. Mine is a w204 2013.) - Sorry for the bump.