W211 e55 AMG - Annoying Flat spot

[dvb247]

Symtom

pull away very slow in 1st (manual mode) press pedal slowly build to 2/3k rpm then big hiccup and back to normal.

pull away in second slowly is the same but less of a jerk

pull away in second quickly (like pulling out on to a round-a-bout) the car then double starts, hard to explain, an immediate flat spot just as the car is pulling away due to the fact that I have pushed the accelerator past the flat spot point straight way.

In reverse it's like a switch.

Is there is some sort of laptop/system like a polygraph that can monitor the car, I only need twenty yards to induce it?

HEEEELLLLLLLPPPPPPPPP!!!!!!!!!!!

 

[skemball]

I'm guessing this car uses a drive by wire electrical throttle so if you have one & know your way round an engine with an electrical multi-meter i would first check the throttle potentiometer for smooth progressive resistance throughout the throttle range.


I'm not familiar with this model so couldnt suggest where its located or what wires to connect to.

 

[dvb247]

It has a Kleemann throttle module fitted but problem was there from before that, will be taking every bit of advise to someone who really can look after an AMG in Cheshire hopefully lol !!!

 

[dvb247]

Grrrrr, it's becoming very apparent that this is standard on 55's, it's the super chargers clutch, blip the throttle early and the car engages the clutch, drive slowly up to 2/2.5k rpm and then the super charger clutch has to engage whilst the engine is now under load thus creating a buck.
Is this true?
I need to drive another 55 to be sure but this seems to be the answer from members of the MBWorld forum?
Any comments or 55 experiences welcome, many thank!

 

[Alps]

im doing a days driving today so i`ll give it a go, i cant say i have noticed any flat spots so far tho.

 

[C240Sport97]

I haven't noticed any flat spots either .. but I have noticed that the gearbox is not as smooth .. they is a very slight almost imperceptible 'thunk' when I take my foot off the throttle quickly

 

[Alps]

when test driving mine used to be rough when pulling up to a roundabout,when i let go of the throttle and then pressed it again to continue it used to be quiet rough, they re-caloibrated the gear changes and its very smooth now. they had to recalibrate on both s and c modes

 

[Bobby Dazzler]

I think that's the torque convertor switching between modes based upon your description. Is it consisently 1500 and 3000 rpm by any chance?

 

[C240Sport97]

when test driving mine used to be rough when pulling up to a roundabout,when i let go of the throttle and then pressed it again to continue it used to be quiet rough, they re-caloibrated the gear changes and its very smooth now. they had to recalibrate on both s and c modes

what do you mean "recalibrate"?

I had the gearbox reset via STAR on Sat, and it is a little better now ...

 

[Bobby Dazzler]

I think that's the torque convertor switching between modes based upon your description. Is it consisently 1500 and 3000 rpm by any chance?

I don't suppose it coinicdes with any of the transition points on this graph does it?

 

[Alps]

140 miles yesterday, cant say im seeing any on the flat spot symptoms like you are!

 

[Alps]

what do you mean "recalibrate"?

I had the gearbox reset via STAR on Sat, and it is a little better now ...

downshift was the problem and when power was reapplied it was revving to high hence a jerk effect, only on gears one and two, they sorted this out by recalibrating each gear, i had to go back and get them to do the same for C mode. apparently its something any of the AMG performance centres can do for you.

 

[dvb247]

Not the same for me, I simply select 1st or leave in 2nd, pull away slowly pressing the accelerator, at 2/3k rpm the car will buck/hiccup/flat spot it's very apparent when driving normally in 2nd or 3rd even, I am told it's the SC clutch not engaging until later coz I'm driving slowly, the work arround is to be more aggressive straight from a standing start, then all I notice is a kind of double start noise, then (I'm told) the SC clutch is engaged and the car is smooth thro the gear, this seems to work for me but would love it to be smooth although now think it is a characteristic with the 55 super charger!
any other 55ers notice this?

 

[Alps]

hi mate, my car gets driven by the missus, very normally during the week with the kids in the back, so an aggressive drive is not how its driven most of the time... again no flat spot, you defo need it looked at, whoever gave you that bulls*it abt the characteristic of a 55 supercharger is having you on!

 

[C240Sport97]

downshift was the problem and when power was reapplied it was revving to high hence a jerk effect, only on gears one and two, they sorted this out by recalibrating each gear, i had to go back and get them to do the same for C mode. apparently its something any of the AMG performance centres can do for you.

reapplying power is fine for me .. it's an almost imperceptible 'thunk' when I take my foot of the throttle quickly

 

[imran1]

Not the same for me, I simply select 1st or leave in 2nd, pull away slowly pressing the accelerator, at 2/3k rpm the car will buck/hiccup/flat spot it's very apparent when driving normally in 2nd or 3rd even, I am told it's the SC clutch not engaging until later coz I'm driving slowly, the work arround is to be more aggressive straight from a standing start, then all I notice is a kind of double start noise, then (I'm told) the SC clutch is engaged and the car is smooth thro the gear, this seems to work for me but would love it to be smooth although now think it is a characteristic with the 55 super charger!
any other 55ers notice this?

hi my friend has an e55 and this same sort of problem happend to him it was one of the bushes in the rear cost him about £300-£600 to repair at an local merc specialist

 

[MOR8A]

Not noticed anything like this in mine but to be honest I have not had it long or done many miles.

 

[Mercgaz]

I have something like this on my e270 cdi on a 2003 plate ...anything further on this?