problem on 2012 c63 when turning slowly
 

HI, I got 2012 c63 coupe. and I forgot when this start happening, it happens only when cold start. im turning out the parking lot or drive way. so I backup the car and turning my steering wheel all the way to left or right and my rpm when up high around 3500rpm and car wont go for 2 second and then I push the gas again the car feel like shocking and start moving back, and I put on drive I push the gas and my rpm acting the same way as backing up, rpm went up high and drop for 2second then go. so idk if it is a common problem with w204, my car is tuned, but not from me, I bought the car 1 year ago from a dealer. so I hear someone said it is my rack and pinion problem??? when my car is warm up as driving after 15min this problem doesn't shows as crazy as cold start. so I want to see if any one can help. sorry my English not that well lol. have a nice day!

Might be the transmission being cold.

I have the same issue , the transmission doesn't want to engage the gear till about 2500 rpm . Your not the only one having this problem , but iv been having trans issues for about a year now with it "flaring" between shifts , and slippage .

When was the last time that the transmission fluid was changed? As automatic transmission are dependent of fluid line pressures within the tranny.
Not enough pressure, the car will not go into gear. I would have the tranny fluid changed for starters.