I have a 99 C230k and was wondering if anyone else out there has the same problem as me.....Well when the car is warm during take off it seems like the car doesnt want to shift to 2nd gear in Drive mode. But when it does want to go to 2nd gear then it jerks the car really hard. It would stay in first gear to about 5000 RPM before it will shift.......plz advise I took my car in today but they said if I can perform the incident again before they will fix the problem even though my car has a 100K warranty on it.

 

i dont quiet have that problem. but i do recognize the same situation, from 1st > 2nd. My car just shifts hard

 

This is totally normal!

Mercedes engineers designed the transmission so that on cold starts, the engine would stay in 2nd (note, NOT 1st gear) gear longer to warm the catalytic converter much quicker; thus, greatly reducing emissions.

When engine coolant temps are below 50d (C), the transmission will hold the car in 2nd gear until either: (a) coolant temp is above 50d C, or (b) when the engine is revved beyond 3,100 RPMs.

If you look in your owner's manual, you'll find the information on this. It warns that this is not a malfunction, but the way the car was designed.

AMGC230k, are you sure you aren't exaggerating about the 5000 RPM? Try it one morning... you'll see that it will shift out @ 3100 RPMs. This feature is partly controlled by a "cold-start" relay... and yes, shifts are, and will be more abrupt until coolant temps rise. So it's all normal!!

 

no this is when my car is already warmed up I know when the car is cold it does this but not when its warm.....

 

Were you driving the car agressively (ie. quick acceleration/deccelaration prior to this occuring)?

The tranny's do have a learning feature that will adjust the shift points to higher rpm's if you are driving in an agressive manner. Therefore, prior to going to my local dragstrip, I will make a few hard standing starts w/full throttle for about an 1/8th mile. Doing so will get my tranny shifting nicely up near 5,600+ from 1st to 2nd, 5300+ 2nd - 3rd, etc.

The car is quicker when it's shifting at higher revs (that's why it pulls hard because it's making more effective use of the torque curve).

From my perspective 5,000+ rpms and hard shifts are a good thing. Of course I'm a bit biased towards performance

If it is a malfunction, it seems like a decent one to be having
Bright side is that if it is and you don't like it... it's covered under your warrenty.

Jason

 

i have same experiience, but the difference is mine only experiencing rough shifting (like someone hit you from behind) when I floor the gas pdeal for instal passing speed.

 

I finally changed out my AT Fluid and Filter. What a difference. Still shifts fairly crisp but, nothing like it was. Who wouldah' thunk it.

Matt