xtyper

I've only got 2K miles on my new 2010, and every so often I get this weird surging or bucking effect when I take off from a stop at light throttle. It only lasts for a couple of seconds until I give it more throttle or take my foot off the gas completely. This event does not seem senstive to whether the car is cold or warm, as it's done it in each case. I always drive in C Mode, and the car is 100% stock.

Anyone else experience this behavior or have an idea what may be causing it? I'm really hoping it's normal and that there's nothing wrong with my car.

bhamg

I've had that also...very, very occasionally, probably once every 2k miles, both pre- and post-tune.

blackc230benzo

Does this sound the same?
https://mbworld.org/forums/c63-amg-w...-cel-help.html

I thought it was an air filter problem but now I think it may be something else. I get a fish bite feeling or random misfire on light throttle. Mostly at higher speeds but sometimes going slow. My car is still in the shop... hopefully will hear something next week

xtyper

Nobody else? I was really hoping there would be more people relating to this behavior.

SonnyakaPig

Count me in. And I have BMC filters. I'm going to take them out soon and give the stock paper filters a try and see if I can make this disappear. I would guess it's the filters in my case, so no big deal.

Edit: The problem with the theory I stated above is that I have never had a CEL and far more importantly, my car has never thrown any codes, of any kind. I had the MB shop foreman (great guy, very experienced, btw) hook my ECU up to their up-to-date diagnostic tool, and they read my car's code history and they found nothing.

So, if my car was misfiring due to the filters, there should be a record of that. If the AFR was too far out-of-whack, my car should register that and record it. I really don't know.

The other possibility is transmission issues. But my trans shifts great in "Manual."

I experience this mostly in "Comfort."

I don't think "Sport" mode is a good mode to see whether the car is having low speed drivability problems, because Sport mode is a twitchy, but fun little ******* in OE form. Sport does all sorts of strange and random things, including downshifting violently at parking lot speeds (this has only happened about 3 times).

In "Manual" mode I never have any problems.

SonnyakaPig

I would stay tuned to what "blackc230" finds out about his car.

Raleighc63

This happened to me when I got K&N filters. Cleaned off the mass air flow's and it fixed the issue..

xtyper

My car is 100% stock with paper filters and only 2K miles, so can't imagine why my mass air flow sensors would be dirty. Still, couldn't hurt to clean them and see if that helps.

bluejae

i've been getting it too... and i have k&n filters...

weird thing is that i think it started when the air got cooler...

any chance the temp has anything to do with it in conjunction with a filter?

PetroC63

I've been running K&N's/no charcoals since 180 miles on my odometer.


Currently, I have a hair over 5,000 miles with no problems. I did have
a CEL once for a stuck purge valve. Technician said it was not related.

andymlow

I have noted the same thing. Totally stock 2009 with 19k miles. Only happens with trann in Comfort mode and only lasts a few seconds. Reported to dealer hoping there was a bulletin or software update and was told, "most people drive it in S mode." Go figure.

edykh

It happen to me too, but i think because is in C mode and it start in second gear. If i use S mode the problem is gone. My car is stock by the way.

SonnyakaPig

I'm starting to think that in addition to this issue occurring mostly in "Comfort" mode for me, it also has to do with the gas that is in my car.

I live in CA so I'm stuck with 91 and my car hates it. When I mix in 100, my car never has this problem in any transmission mode.

Also, not all 91 is the same and I'm starting to think that 91 octane is becoming increaslingly inconsistent from it's stated 91 octane rating.

Some might say, "you're being overly sensitive to what you perceive your car is doing." I would reply, because the C63 is a performance car, it manifests octane issues much more clearly than a random car that can be fed 87 octane.

Sincity

What RPMS does it happen in? I have a shifting issue in S and the 2-3 shift at 4k RPM.

OrientBlue3

I experience this as well. Mainly right after start up.

b16

Same happens to me. I have a tune, rest is stock. 09 with almost 60k miles on it.

CoolBDPhenom03

You can add me to the list. Especially after a cold start.

kaunain13

Same. I just drove around and it's 15 degrees here. In C it would jerk from stand still but stopped after I put it in sport and the engine got warmer. My car is stock 2013 with less than 50 miles.

SaphGreyC63

Jerky for me sometimes in S+ going from 1st to second. Engine warm. Very rare.

ruey220

so people just gave up on this issue?

KIS007

It's happened in both my M3 and my C63 and I believe it is when you're out of sync with the car when you're accelerating.

mstrbenztech

Ok guys here may be some info on what most of you are feeling. This bucking is the wet clutch assembly. They started using a wet clutch assembly instead of a torque converter in the 2009 E 63 and SL 63's. In 2011 the S63 and CL63 and then finally in 2012 the CLS and C63's. This helps with initial takeoff and also for racestart mode. It basically looks like a small torque converter. There is a lengthy adaptation process we do with the SDS but usually that does not help very much. I replaced many of these wet clutches and have not had any other issues. Most of them are about 90% better after replacement but you still may have a very slight bucking/jerking. You usually only notice it during slower takeoffs so most customers don't mind it. THis is just some info, you may have other problems but this sounds like what most of you are feeling.

Diabolis

The first 13 posts in the thread were all written in 2010 before someone resurrected it last year. The C63 didn't get the MCT until 2012, so it's certainly not clutch bucking as all of the early posts (and some of the newer ones) are experiencing it on pre-MCT cars. While the clutch may occasionally judder in C mode at takeoff on a cold MCT car as you said, it's not the case with the majority of the posts here.

cyberorth

Well said. I consider it normal. It is when the car expects a more sporty behavior from me and I hesitate for a fraction of a second, then I have to correct by lifting or flooring. E46 M3 was also the same with manual tranny.
IMO it's not the car, but the driver.

ruey220

the more you try to adapt to it the more it confuses the adaptive tranny shiftpoints. my brother's wife basically screwed the adaptive system with the way she drives to the point the dealer couldn't fix the problem of stalling and they replaced their GL due to the lemon law. If you are pressing the gas normally this shouldn't happen.

It makes me feel like the throttle position sensor or electronic throttle body solenoid is failing. I had that issue in another car before. very unreliable feeling.