Light tap on a gas pedal creates hight RPMs and slow return to idle gear lever in N p

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Nov 25, 2024 | 12:05 PM
  #1  
Very strange engine behaviour. Even a light tap creates this high rpms and slow return to idle also there is a less power until 2000rpms. I installed new gas pedal and new MAF sensor without any change, also i have fixed all vacuum air leaks. No check engine light. Here is the video with the issue
https://youtu.be/7dKPIf3lqOg?si=qij3CT67jedTb_eh
Reply 0
Nov 26, 2024 | 05:16 AM
  #2  
u r going to need proper diagnostics - on this model you almost can't open the door without dealer tools plugged in to keep the software behaving - expecting to fix weird engine management stuff with guess work is unlikely to be a fun or speedy experience

as a quick fix - one could try and reset the throttle damper - a silly pedal calibration using dealer tools (of course check out the many faults of doom after wiping the crap and then driving for a few mins to see what's actually real

if you are going to run an S class from more than 10 mins join this

https://mbworld.org/forums/s-class-w...a-s-n-1-a.html



Reply 1
Nov 26, 2024 | 01:54 PM
  #3  
Can't really tell as I can't see your feet, but looks normal to me.
Reply 0
Nov 26, 2024 | 02:15 PM
  #4  
No no, totally not normal. I am just stepping and release very fast a pedal and rpms are still rising and veery slow going back to idle. Its just like there is a vacuum leak and someone is spraying carbon cleaner right there on a leak. Also the car is sluggish until 2000rpms when in drive and when climbing a little bit noisy, sounds like BUUU! Smoked everywhere with smoke machine even thru two "EGR" valves and smoke is coming out from the exhaust freely. There is a slight vibration at idle. Engine and ATF mounts changed months ago(lemforders). New spark plugs and injectors cleaned and tested with stand, one was not so good and i change it.
Reply 0
Nov 26, 2024 | 02:25 PM
  #5  
Hard to say. Pull codes.
Reply 0
Nov 26, 2024 | 02:54 PM
  #6  
Not even one...i am waiting for my xentry diag and will try all the adaptations and magic tricks too see if helps. Not sure if there is some codes which my cheap diag is simply not detecting/reading. Soon 😀
Reply 0
Nov 26, 2024 | 03:05 PM
  #7  
That is correct, the standard OBDII system will not read the more complex, proprietary Mercedes codes, sadly. I have a gut feeling you have a TPS-APS sensor communication issue.
Reply 1
Nov 26, 2024 | 04:35 PM
  #8  
smoke ? that doesn't sound good - that's not just sensors
Reply 0

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Nov 26, 2024 | 04:47 PM
  #9  
Quote: smoke ? that doesn't sound good - that's not just sensors
No no, i mean i used smoke machine to test airflow via CATs. I used "EGR"s holes to plug smoke machine hose 😁
Reply 0
Nov 29, 2024 | 03:57 AM
  #10  
Ok people, i have a xentry diag with me now. Connected and no fault codes. Any ideas? What to check? Actuations? Adaptations?
Reply 0
Nov 29, 2024 | 04:29 AM
  #11  
Throttle Damper... reset calibration - its in the Engine ECU section

I now believe this should be done whenever the Rear SAM is flashed - it seems to affect throttle usage of cruise on cars with radar cruise (distronic plus)

For now I would not touch the adaptions
Reply 1
Nov 30, 2024 | 06:03 AM
  #12  
Xentry showing me -48°C and coolant temp -48...
Reply 0
Nov 30, 2024 | 06:14 AM
  #13  
And what about this?
Reply 0
Nov 30, 2024 | 08:28 AM
  #14  
clearly its not very happy

I'd clear the guff about camshafts and see if it comes back - (quite normal, often its the sensors are playing up) clear and see what happens

But the coolant temp needs sorting - doubt its off the stat connector.... find another engine temp sensor and replace it ? - and or double check the software part number for the engine ECU SW - they did an update it should have had from years back

don't forget its a Merc they fit extras in software to achieve unknown goals - some later models they discovered special trick with ambient temps making them throw engine lights - and the early map also had tighter tolerances to throw camshaft position errors

Might be air intake sensor as thats showing silly....
Reply 1
Nov 30, 2024 | 08:31 AM
  #15  
great with such a small picture .... 0117 number of teeth on sensor rotor too high

WHAT'S THAT ABOUT ?
Reply 0
Dec 1, 2024 | 09:46 AM
  #16  
My fault! Ignition needs to be ON and then the temps are ok! Sorry about that...What about these values


Reply 0
Dec 1, 2024 | 12:52 PM
  #17  
is this a wind up ?

the ignition switch pop up is the simulation (practice) version ?
Reply 0
Dec 1, 2024 | 01:46 PM
  #18  
Quote: is this a wind up ?

the ignition switch pop up is the simulation (practice) version ?
i cant understand you .
Reply 0
Dec 1, 2024 | 03:37 PM
  #19  
in your pictures at the top middle - it shows how to turn on and off the ignition key with a tick box - that how you play when in the learning version of the toy

open Xentry not Xentry simulation and you have a chance to diagnose the car not play games
Reply 0
Dec 15, 2024 | 06:45 PM
  #20  
Any updates?
Reply 0
Jan 8, 2025 | 01:06 PM
  #21  
What about these values?
https://youtu.be/yNGSeu0rq7M?si=QRKn9xl6q31d9XLL
Reply 0
Jan 8, 2025 | 05:04 PM
  #22  
I was messing with coils testing them with some spraying water on them in the dark to see if there is spark fault. Finding nothing wrong, but i decided to continue the search... ending to mess with the PCV valve and when i shut it some strange noises appears. This whinning/whistle noise is there always but after i shut the PCV breather with finger the noise is getting stronger
Reply 0
Jan 8, 2025 | 06:28 PM
  #23  
Continue digging:
https://www.reddit.com/r/mercedes_be...ver_is_closed/

And after reading the comments:

Tomorrow i'm going to my car repair shop. Stay tuned...
Reply 0
Jan 9, 2025 | 04:40 AM
  #24  
crank vibration damper .... but the CPS is at the back running off the flywheel
Reply 0
Jan 9, 2025 | 04:53 AM
  #25  
Quote: crank vibration damper .... but the CPS is at the back running off the flywheel
I think my front crankshaft seal is bad and the engine is sucking air from there. I hope the back one is still ok...
Reply 0
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