Jordan Bi

When cruising in comfort mode at 5th or 6th gear, if I press the paddle the car starts to accelerate but shakes pretty noticbaely. It feels like the engine is lugging because the transmission isn't downshifting and all that torque is just accelerating the car by force. I've done transmission resets, checked the selenoids etc. has any of you experience similar problems?

Plutoe

At any time when you are playing around did the CEL go off??

Jordan Bi

Nope, the only time it went off was when I first picked it up in Europe, they never found a problem, cleared it, and CEL never came up again

ItalianJoe1

If you step down further so it actually downshifts, does it feel ok?

It does lug the engine at low rpms with light throttle, because it's more efficient and helps gas mileage. But you can easily override that with sport mode, or slightly more throttle.

Jordan Bi

yes if I press it hard enough it will downshift 2 gears, and the problem is very very rare in sport mode. It's just it gets annoying when trying to pass on highways

PUGPROUD

You might try searching the internet under "reprograming automatic transmissions" for advice or places that will do diagnostic fix. Just a thought...

BillyD

There's certainly something wrong with your vehicle. I've had my S63 Cab over 150 mph several times while I was in Germany about 2 weeks ago. No "shaking" at all and rock steady.

Hope this helps.
Bill

amgts_416

Hey im having the same problem. Noticed it happens more aggressively when in comfort and boost passes half way point on the dash. Wondering if you found out what the problem was and how can i fix it?

GMBALL

I have same issue, 2015 S63 M157. Only in comfort mode and does not happen often, but ocasionally,

amir1

Misfiring? Bad Coils? Bad plugs? Bad Injectors?

GMBALL

nope, this is different. This is the tranny. I am doing TCU soon. I will also replace stock plugs with one step colder ones.

GMBALL

Update: after installing Weistec TCU - the issue disappeared completely. As a matter of fact, it even changed the car. The transmission is more fluent and much less harsh during normal driving, and much more aggressive and quick during aggressive driving. I now finally understand why TCU is one of most critical upgrades. Much recommended.

I haven’t measured acceleration differences, will do so when my BlackBoost intake arrives and is installed.

Are you modded or bone stock? I started having these issues only after ECU tune.

GMBALL

Actually, I have to reverse my opinion. After many months of driving with this Weistec TCU and a lot of measuring of the acceleration times, all I can say - there is no improvement acceleration wise. It's literally the same. Maybe 5% at most, but that can be to elevation, outside temperature, small differences of the angle of the road, etc. I believe my positive opinion was based a very subjective feeling right after I've bought it. What it really did that it made shifting less harsh and much more fluent with a modded car and a high torque (1150NM). Other than that, don't expect what guys are saying here - that TCU tune is actually better than ECU tune and car with TCU tune is almost as fast as with an ECU tune. That is a total BS.

andymlow

Motor mounts?

JohnLane

TCU tune will change the character of the transmission but does not add torque or Horsepower. Have to turn up the lump in front of the box for that.

GMBALL

My understanding was that TCU increases torque limits in lower gears, where it is limited and thus allowing for a slightly better acceleration. At least, this is what Weistec says:

The Weistec TCU tune results in faster and more firm shifts. This is accomplished with faster target shift times and running higher line pressure which also has the added benefit of reducing slip and increasing the torque capacity of the transmission. With higher line pressure, the clutches in the transmission are clamped harder making for better grip which directly allows the transmission to hold more torque. With less slip and faster shifts, the lifespan of the transmission is typically improved as well.Key Features

• Faster Shifts
• Firmer Shifts
• Increased Line Pressure
• Increased Torque Capacity

JohnLane

Note that there is no mention of increased horsepower or torque made in front of the box. The engine makes power. Transmission multiplies torque in reduction ratios and divides torque in overdriven ratios. With the installed software your transmission should be more amusing but things get exciting when the engine is asked to produce more.

Bigg Willi

Mine does that too, feels like the transmission is hitting air bubbles in the fluid? Gonna try a trans update with the BenzNinja.
Now I know it's a Car issue.

Bigg Willi

Yes Sir! Replaced the coils and plugs, and the shudders are completely gone, car is back to being just stupid fast and smooth. I really though it was the transmission, but I'm glad it wasn't. Already got more new plugs as they seem to last only about 40kmi, gonna get new coils too as you'll tear them up on removal. The joys of owning a super car..lol

JohnLane

Guys.... Get ahold of Peter... AKA BenzNinja. Buy the computer, multiplexer and a membership. Have Peter give your car some software changes. He offers one that makes for an additional mode for the transmission (Sport +) that also changes how it behaves in sport. Before that my transmission was slow to downshift, would ‘thump’ a 2-3 shift and generally felt like it could be a lot better. Couldn’t be happier with the results. Be sure to also give it Intelligent Lighting. Another of those things not enabled due to our friends in government. He offers a long list of software changes and will gladly assist anytime you have an issue with the car. My car also got ‘remember last mode’ so I don’t have to disable Stop-Start every time I start the car.

SL55inMD

Hi, I came across your comment here and wondering if my 2013 ml63 (m157) has the same issue - it’s shaking/shuddering on acceleration - while in the same gear, not while shifting gears. Did you have the same symptoms? Thanks

Bigg Willi

In a word YES.. These engine are hard on plugs, I'd say change them every 40 - 60kmi. Also the Beru OE coils don't seem too robust, I switched to TRQ, they seemed to have addressed all of the OE coils faults. Bad O2 sensors can also cause our issue so that's next on my list. Good luck!

SL55inMD

So the plug and coil replacement didn't fix your issue fully? I'd imagine a bad O2 sensor would throw a code a scanner would pick up, no? My current issue seemingly isn't throwing any relevant codes (transmission or engine). Also the car has 65k miles/104k km and I don't believe the plugs have been changed yet. I just bought the car and noticed the shaking on acceleration on the highway on the 3 hour drive home. It wasn't apparent to me on the test drive and the PPI i had done on at a MB dealer did not mention anything about it. Pretty concerned/angry to say the least.

Bigg Willi

Yes the coil and plug change did 100% fix my issue, just giving you what could be another cause of the issue with the O2 sensors.
Funny thing is, my CarFax said the plugs had been changed at 42kmi, but looking at them with now 60kmi I don't think they were. Change your plugs, it just can't hurt.
O2 = I had a 2003 G35, when I replaced all 4 O2 sensors one was completely broken off, it NEVER threw a code. O2 sensors can also get slow over time and not throw a code so I change mine every 60 - 70kmi.

SL55inMD

Got it, thanks again for the feedback. Ordered up the parts today and will tackle soon. fingers crossed this violent bucking of the motor is all due to spent plugs.