malahhaor

Hi all. I tried to research, i promise. But this is a little different from the usual transmission questions.
I test drove 2013 C63 coupe with P31 and liked the car. But something was strange about transmission. It shifts just fine between the gears but when you are standing at the light, once in a while i started feeling some sort of knocking through the pedals. Almost like clutch is out of balance, but would go away here and there. If standing in park, noting. Place it in Reverse or Drive and keep holding the brake it will show up.
Also when in that sweet spot between dead stop and full brake release, if you just let the car roll but still hold it back with brakes, you feel some strange jerking. Almost as if the clutch is being engaged and disengaged supper quickly. I had that same strange feel on my 07 S550 but that had a torque converter. Also in the S class i could easily replicate that if i just let the car roll on its own when slightly up hill. It would constantly have tiny jerking feel to it.
I'm afraid that something may be wrong on this C63 and develop in to big issues. The car already has almost 50K on the clock.

Any input would be greatly appreciated.

95gsrturbo

If its under 50k depending on the birthday it may be under warranty.

Have MB look at it under warranty before you buy. Some MB dealers have a specific AMG mechanic you want to ask and have them drive it WITH YOU if possible

I had to do this.

PeterUbers

Welcome to the mct trans.... That's not atypical of the mct... Same at times in my 2014 e63S with 10,000 very easy miles on it (bought it new)

In comfort mode it should be smooth ... In s or s+ it's more temperamental

I'm trying to figure out the first part of your question ... The knocking while totally stopped at a light... I don't have that

malahhaor

Yes, when at full stop, holding the brakes it feels as if someone is knocking on the frame of the car. cant really hear it, but sure feel it through pedals and what not.

zcct04

That knocking sounds a bit like what people have described as the sensation you get when the motor mounts have failed.

CarHopper

audible knock = motor mounts.

no knock, but shake = 6.2L v8.

Sweet spot shake under slow brake release = the point where your pads are barely grabbing the rotor causing a skip.

I'd pay attention to a slipping tranny. If you're standing on the brakes at a light and the car feels like it is shaking or you feel a tapping through the pedal it's pretty normal. If you're just releasing the brakes and you get a skipping thats the brakes releasing from the rotor. If you can actually hear a knocking it is likely the mounts are bad, and depending on miles, this can happen.

malahhaor

thank you guys, its most appreciated.

s.e.a.n.

Shaking and tapping sound is normal! It took time for me to adjust coming from a 4 cylinder.

malahhaor

Well, small lifter tapping noise is ok, i can hear that when under the hood. some small vibrations is ok, it is a big engine with allot of weight being thrown around. but distinct knocking feeling when in gear is worrisome to me.

I found a 2012 with same mileage close to me, will go and drive that one to compare.

95gsrturbo

To all of you saying the tapping and shake is normal.

I have a 12 p31 coupe ... its a Mercedes and it acts like one..... its perfectly quiet and smooth.

Car drives and sounds like an S class until I'm on throttle

jmueller

OP. Your symptoms sound very similar to the ones I had when my motor and trans mounts needed replacing. I had mine changed a year ago under warranty and I have a 2012. Thus, your potential purchase likely has the same age on it.

Once my motor and trans mounts were swapped, my car ended up feeling like the car that 95gsturbo is describing.

malahhaor

thank you guys, its most helpful

skratch77

My car is a 13p31 and the MCT is rough and u can feel it engage the clutches coming to a stop and definitely feel it while taking off at a light.

There is no torque converter to buffer the gear changes and is 100% normal.I actually like the feel of the 2011 7 speed around town in traffic but nothing beats the shifts and downshifts our MCT have over the 7 speeds with tourqe converters.

I hate when u drive the car hard and then come to a stop and in m mode,you can feel the downshifts coming to a stop and makes the rolling stop not that smooth as the clutches change gears.

TurboRush

+1 - little shake at idle is big motor problems I also feel a light tapping in the brake pedal which I researched when I first got the car and confirmed it was normal. Knocking or something actually audible is not.

Also, it might be worth doing the MCT reset procedure if you can - that resets self learning back to how it came to the factory and tends to smooth things out especially when it gets a little clunky on the down shifts.

95gsrturbo

^^ i have no tapping when holding the brake.

Is that something i should be worried about?

TurboRush

Oh, that's very bad. Your rotator splints are going to break any day!

PeterUbers

+1

I want the smooth city driving of a torque convertor and the low drivetrain losses and quick shifting of an mct/dct

Hmmm.... Pdk, Audi, zf?

TurboRush

Not to take this thread off topic - but my friend has 2012 S4 and the car shakes/rough at idle, little clunky here and there and I recently had a new Audi (2015) as a rental and the transmission was just terrible - clunk through every gear on down shift, 4 - 3, clunk 3 - 2 clunk, 2 - 1 clunk and it seemed to get worse the more I drove it (1k in all)...immediate upshifting even when giving it moderate throttle. Absolutely terrible.

I am not saying the MCT is the greatest but I am not so sure the grass is much greener on the other side.

PeterUbers

Interesting

The only thing distasteful about my mct is the low speed engagement and disengagement of quickly stopping to a near total stop as then jumping on the gas immediately and the "stumble" that is well described by most 2014-2015 e63 owners (in s or s+)

CarHopper

No, nothing to worry about. Some people actually end up driving themselves crazy over the tapping refusing to accept what is going on 2 feet in front of their foot.


As for trannies. The MB mct isn't the best out there, but also not the worst. I do hate the delay and what not, but I've driven much worse.

That said, I'm jealous of my neighbors m3 tranny, thing is awesome. Someone else mentioned PDK's which are also very sweet.

Anyways