droppolo

Hi guys, new forum user and recent S55 purchaser (first time benz owner too). My car is a 2006 model with 60k miles and in flawless condition. I could not be happier with this thing in all aspects. I came out of a 2008 LS460 and am very happy with my choice.

Moving right along. Recently my car started giving me a slight problem that I hope won't end up being costly. I figured I'd run it by the board before going any further. Here's what happens. Upon acceleration from a stop there tends to be a slight hesitation most of the time. The best way I can describe it is this. Imagine if you were sitting way back in your seat, foot barely touching the accelerator and you nailed it from a dead stop. The force would cause you to slide back in your seat pulling your foot off the pedal which would cause the car to slow down, pushing you forward again back onto the pedal, which in turn would cause you to slide back off the pedal, etc etc. It's a very slight bucking maybe 1 or 2 times but after that, smooth as glass.

Does this sound even remotely familiar to anyone that has had some S class experience? I did some searching around here and found nothing similar. I could have searched the wrong terms, however.

Any help would be greatly appreciated. Looking forward to having a long relationship with this baby.

Here are a couple of pics

wpgfordguy

Nice car, sounds like the traction control is coming on. Don't panic

Efivehundred

Does the ESP light in the instrument cluster flash in the S class when it's intervening?

droppolo

No lights come on when this is taking place.

Thank you for the reply.

ShangoAshe

It's your torque limiter kicking in. Best way to maximize your car's performance and get rid of the jittery throttle contact Jeremy@OETuning.com

He's a sponsor here and he does ECU Tuning for a lot of cars. I would suggest you contacting him.

droppolo

Is it normal for this to start happening after 2 months of driving with no issues? I'm not really looking for anything more than to eliminate this from happening. I'll give him a shout though. Thank you.

ShangoAshe

No problem. It is completely normal! The hesitation in the throttle is your ECU Torque Limiter trying to cut down the power and preventing you from going too crazy. No issues really it's completely normal.

It just means you got a heavy foot!

droppolo

That would make sense except for a couple of things:

1. It started doing it out of the blue one day
2. I drive like a 70 year old woman

Flight Test

Could possibly be a motor mount going bad. The motor torques over against the mechanical limits and you feel a bang or hesitation. I am assuming from your description that it happens under very low load conditions, is that correct? What about large accellerator imputs?

droppolo

Correct. Since this started i've been a little concerned so i've not 'punched it' to see what happens. I guess I could try that though.

MB-Dude

Droppolo - Are you sensing any serious vibration or what may be perceived as 'stuttering' of the car as if there is a deep, rapid-fire metal-on-metal banging? If so, try accelerating moderately quickly on an interstate onramp and allow the engine to gain higher RPM's. While watching the tachometer, do you perceive any of the unusual symptoms at a particular RPM range? Focus especially in the range of 2,000 to 3,000 RPM. Then try and maintain a steady speed at that RPM range. Does the symptom subside greatly when the engine is at the steady speed, driving steadily down the road?

My '05 S55 exhibited these symptoms and I had to replace all 3 mounts (2x engine and 1x transmission). Symptoms disappeared immediately. While I still need to find the root cause of my 2,500 RPM vibration (I think I know what it is), the horrible driving sensation is gone.

FWIW and food for thought.
Cheers,
Jeff

droppolo

No, Jeff, nothing like that at all. My only symptom is the stuttering I mentioned in my first post. I'm going to try some different accelerations after work this evening and see if I can get any more information. Meanwhile, I made an appt at the local benz dealership. Fingers crossed

Thanks for the reply

jwalther

I'm a new owner as well, and experience the same sensation. I thought I had a tranny issue, but have been assured by both the Dealer and my Indy that it's the torqe limiter. I think you'll get the same answer. Good luck!

mrbenzes

If it has happened out of the blue, can you tell if it is worse when the car is cold..and I mean the transmission fluid?
There is a baffle that is there to smooth the power transmission that can go bad...it looks like a black light bulb and serves to baffle the fluid through the pumps somehow. I have read of other users replacing it on this forum. My 2005 car does this a bit when cold but it goes away fairly quickly. If you dont see the yellow triangle flash on the dash when you experience the delay it may not be the torque control cutting power.
The baffle can be replaced as DIY, i have read, but I havent tried mine.
At 60K miles, you might want to change your tranny fluid anyway...that is a good time to replace the baffle.
Let me know if you want me to get you more info.
You have a goegeous car by the way...great color!
Mike

droppolo

What kind of price did they give you on replacing/repairing it?

That's some good info, Mike. I'm going to see if I can ascertain if the fluid has been changed. Cold or hot doesn't matter though. It always does it.

Thanks for the compliment!

mrbenzes

I'm not sure what the whole repair cost was, but the part was not too expensive..maybe $150...it was called some type of compensator..I'll try to get more info and post it here.

Mike

droppolo

Thank you.

I found a Mercedes mechanic who is mobile and fully equipped for anything up to a 2011. Comes very highly recommended by some auto repair shops in my area. He said he knows exactly what it is and will be out here Monday afternoon to check it out. I'll post the results when he's done.

w4sim

Although iv asked in the other thread, i guess i can always ask again, what colour is your car and do you have any more pics of it?

One of the nest standard ones iv seen so far.

droppolo

Answered in the other thread. thanks!

droppolo

Ok well here's the diagnosis. Feel free to discuss or offer your thoughts.

The local benz dealer here has a mobile service so I had a tech come out and take my car for a spin. He spent about an hour with it doing a full diagnosis which included a check of the torque convertor and a few other things he suspected. They all turned out to be working fine. The official diagnosis is the super charger clutch. He said that all super charged cars have this issue although some are more pronounced than others and mine was as clunky as he has seen. He found that by driving the car in manual transmission mode that it was much smoother. After that he did some adjustments to 1st and 2nd gear (whatever that means) which reduced the bucking by about 75% and to what I deem tolerable.

The best part about it is that they didn't charge me a single dime. Never thought i'd see that but he stated that his boss told him to comp this one in order to gain future business. I found that to be very professional.

Thanks for all the advice!

ShangoAshe

I could be wrong... But from my understanding you can't just adjust 1st and 2nd gear and reduce bucking, and not being offensive but it sounds like a load of bull on his part.

So I'm glad he didn't charge you anything for the so called adjustments because if they charged you I'd get on his *** immediately.

If something was wrong with your supercharger clutch you would know it for sure, you don't get any "bucking". The hesitation and bucking isn't even a symptom for a supercharger clutch failure.

But like i said, I could be wrong,

droppolo

I've been in the automotive biz for 20 years and when he explained it all to me I had the same reaction as you. I may have worded the 'adjustment' part wrong, but he definitely said he did something to the 1st and possibly 2nd gears. I couldn't argue with the guy as he's been doing Mercedes for 18 years, and AMG cars specifically for about half of that. If there is any problem here, it's in my translation of what he said to me

As far as the clutch goes, he didn't state it was a failure, just the the buck is caused by how the clutch operates. Some cars do it worse than others. After further investigation, I did find that I was only getting one 'buck' upon accelerating. The 2 or 3 that followed was a result of my foot on the gas pedal during the initial buck.

That all being said, whatever he did definitely had a tremendous affect on the problem. It's barely noticeable.

ShangoAshe

No worries! I'm glad at least it was sorted out from the sounds of it so cudos to you!

I'm sorry if I sounded a bit of an a** but yah, just glad you have everything figured out

droppolo

You didn't... i've been around automotive forums long enough to know about mechanics pulling shady crap. Glad someone was interested enough to show concern

bzliteyear

ditto on beautiful car and color.
what are are you in, and which dealer did the MB mobile?
i don't think ANY dealer in CA does that.
Patrick