My 2024 C43 has recently had an issue where I engage launch control (following the correct steps) and when I release after it’s ready, the car goes up to around 15-20mph but just stops accelerating, and won’t upshift or seem to make any other move. It gets jerky but after like 3 seconds of it fighting for its life it resumes to accelerating. I am due for an oil change, which I’m getting soon but I’m wondering what this could be?

Temps are all good and the cars tires aren’t bad by any means.

 

I bought a used c43 with 1500km on it in April and I had the same issue, all temps ok but when i release the break in goes away in about 1 sec then it slips on the gearbox and makes a whining noise, then it put in the second gear and it goes away as normal.
I have the trackpace option so I could time it and in the 0-60 it timed around 5,5-5,7 the three times I tried it, took it to the dealer an talked to a mechanic who then took a ride with me so I could show him how it behaved, they took the car in for a day.
He told me he did an update and some adjustments in the software for the gearbox, instructions he had to get from Germany as they never had done this before.
I picked the car up and drove home, took it out for a run and did a test at the launch control, it drove away in a very good acceleration and did not hesitate or slipped on the gearbox, tried a few times and did times around 4,4-4,6sec.
So I think it's a adaptation of the gearbox that needs to be done, and I think it's different to the c43 than the one for the c300 so I hope you get a mechanic that know how and are listening to your complaints.