clk209nic

Guys been having this issue with my transmission now for about 6 months. At slow speeds on normal driving i am expierancing gear slipage like the clutches are worn. anything under 4,000 rpm the needle bounces and then catches a gear. At high speed driving, at full throttle the car performs brilliantly with no slipage. After 5+ visits at Mercedes center they cannot find any faults, errors with the car.

Had it three times into the same dealer with no faulty codes and no errors. Updated and reseted adaptations and nothing changed. Now on Monday i took it to another Mercedes dealer, another franchise which they wanted to perform the gearbox service, filter, which i authrosied as my transsmisson service was last down 35k ago, and had the also replace the differential oil which i requested.
Had the car updated and adaptations reset and re taught the gears and the issue i am having is still there.

I have been informed now they can either remove the gearbox, inpsect and relpace any parts they might think are worn or order a brand new gearbox at a cost of 13,000 euro + fitting.

Can i get some advice from some one, as i never had this issue with my pre facilft C63. Has anyone expieranced this type of issue before and what was the problem as i searched high and low and not getting a clear answer by anyone. I am thinking maybe there is a solinoid fault ??? I am tired of no one able to fix me car.

Much appreciated

BalanBro

Is your car tuned? The symptoms you are describing are reasonably common on tuned cars with MCT transmissions (slipping during normal driving, but perfect at WOT). Mine was like this as well, until I had it custom tuned by @hachiroku (eightysixtuned), which completely eliminated the slipping in my case.

My understanding is some of the "off the shelf" tunes manipulate the torque management, which can lead to slippage an low or part throttle. One way to quickly diagnose your issue is to flash it back to stock (assuming you have the ability to do so). This issue should disappear quickly if it was tune related.

Of course, if the car was tuned by a previous owner, you may not be able to do this.

Slow_c63

iTrader: (1)

Sounds very similar to what I’m experiencing right now at low RPMs. Not as bad but the symptoms are somewhat similar. Mine has hard time settling down when coming to a stop and can be very shaky getting on it from a dead stop. Almost as if I’m 7 years old all over again trying to learn how to drive a manual in a mk1 golf. That’s how the car acts under 1k rpm any time I get on it. We adjusted the tune and while it helped a bit, the problem is still there.

I replaced the sparks, injectors, tranny mount, engine mount, tranny service, filters, intake boxes with no help. Next up is the PCV, IM gaskets, and TB plate.

I’ll let you know if I discover anything.

Boostaholic84

My car has been doing this for almost a year. When the car is cold the issue is not very noticeable, but once I’ve been driving for a while the problem is very noticeable, especially in comfort mode. While driving in manual mode the car does buck a little bit at very low rpm’s when taking off from a stop. It’s been very frustrating trying to diagnose the problem since there are no issues at full throttle. My car is tuned, but the issue was present pre tune. The odometer just hit 59k miles.

Slow_c63

iTrader: (1)

You pretty much just described my car to a point. My car is also tuned, FBO, larger injectors, etc… I’m at 54k miles right now. I didn't have this problem prior to doing LTH and putting in ROWs and tuning the car. It feels like a vacuum leak, or PCV related, so I’m hoping that changing out the PCV eliminates this finally. Or else I’m not sure what to do…

Boostaholic84

My car only has ROW’s and a tune, as far as engine mods. I had the ROW’s for about a year before I noticed the problem

Slow_c63

iTrader: (1)

Might be your PCV then. I think our cars are leaning out and I believe the PCV is to blame for our issue. I’ve done plenty of reading and these symptoms went away after individuals replaced their PCV.

PCV is no easy task and I no longer trust any mechanics to work on my car. So I’m waiting for better weather in GA as I’m no fan of working on cars in 90-100 weather with like 80-99% humidity.

When I’m in the right state of mind and weather finally cools down I’ll be ripping the IM out and replacing the above.

Boostaholic84

Were you ever able to solve this issue? I’m very curious

hachiroku

honestly sounds like an issue with a shelf tune. specific branded shelf tunes are awesome at full throttle, but anywhere else the transmission feels like its slipping as well as shifting at the wrong times. exactly as described in the original post.

but lets see what the original poster reports back to us.

Boostaholic84

This was happening before my car was tuned

roadtalontsi

Post a video. It's likely a bad clutch pack or valve body problem.

Slow_c63

iTrader: (1)

This is what I’m narrowing mine down to, as well.

I changed everything, from pcv, im gaskets, tb plate, injectors, sparkplugs, transmission service, same problem.

Now I need to educate myself in the procedure of replacing the valve body, and what all is required for the repair.

CG93

Hi do you still have this problem? or did you fix it, i have the same problem right now at my c63 w204 with mct gearbox

Koyafresh

i had all the symptoms you all had. Check your mct "converter" pack.

Boostaholic84

I ended up needing a new transmission