RPM issues
MBWorld Fanatic!
Joined: Oct 2008
Posts: 2,601
Likes: 28
From: Atlanta, GA
2008 C300 Sport 6 Speed Manual, 1953 Chevy Bel-Air, 2015 Audi allroad, 1963 Chevy Apache
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
So you guys really think it the ECU needing to be reflash, or is it a suggestion. And BTW "ECU gremlin", might be a silly question but is that another way of saying it could be an ECU issue? Can we reflash the ECU ourself? Thanks
Last edited by charliele729; Mar 12, 2010 at 07:20 PM.
Newbie
Joined: Mar 2010
Posts: 4
Likes: 0
2010 C300 Sport
I hate to tell you this...
I have a 2 week old 2010 C300. Does the exact same thing, the tach needles moves a little bit "dances up down ever so slight" specially at low rpm under 2k and with light throttle.
I don't hear nor sense any surging in the engine and the car speed is perfectly constant with constant pedal pressure.
It does not bother me one bit, and I will not have the local gorillas at the dealership tearing all over the car.
I don't think what you have is a problem, could be a design flaw more than anything else in some electronic component.
I don't hear nor sense any surging in the engine and the car speed is perfectly constant with constant pedal pressure.
It does not bother me one bit, and I will not have the local gorillas at the dealership tearing all over the car.
I don't think what you have is a problem, could be a design flaw more than anything else in some electronic component.
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
I have a 2 week old 2010 C300. Does the exact same thing, the tach needles moves a little bit "dances up down ever so slight" specially at low rpm under 2k and with light throttle.
I don't hear nor sense any surging in the engine and the car speed is perfectly constant with constant pedal pressure.
It does not bother me one bit, and I will not have the local gorillas at the dealership tearing all over the car.
I don't think what you have is a problem, could be a design flaw more than anything else in some electronic component.
I don't hear nor sense any surging in the engine and the car speed is perfectly constant with constant pedal pressure.
It does not bother me one bit, and I will not have the local gorillas at the dealership tearing all over the car.
I don't think what you have is a problem, could be a design flaw more than anything else in some electronic component.
Newbie
Joined: Mar 2010
Posts: 4
Likes: 0
2010 C300 Sport
I think my car does it all the time, it is EXACTLY the same as the video that was posted on this thread. Again, since the car drives smoothly, I don't stare at the needle.
It does not bother me much. I am pretty sensitive to how the car/engine/steering are working but on this car, I just don't detect anything not working right in terms of how the engine is running.
I think it is up to you, but it looks like they have gone over the car, the ECU, codes, etc. and replaced parts to no avail. Do you really want them to keep tinkering with your car, if there is no driveability problem?
It does not bother me much. I am pretty sensitive to how the car/engine/steering are working but on this car, I just don't detect anything not working right in terms of how the engine is running.
I think it is up to you, but it looks like they have gone over the car, the ECU, codes, etc. and replaced parts to no avail. Do you really want them to keep tinkering with your car, if there is no driveability problem?
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
I think my car does it all the time, it is EXACTLY the same as the video that was posted on this thread. Again, since the car drives smoothly, I don't stare at the needle.
It does not bother me much. I am pretty sensitive to how the car/engine/steering are working but on this car, I just don't detect anything not working right in terms of how the engine is running.
I think it is up to you, but it looks like they have gone over the car, the ECU, codes, etc. and replaced parts to no avail. Do you really want them to keep tinkering with your car, if there is no driveability problem?
It does not bother me much. I am pretty sensitive to how the car/engine/steering are working but on this car, I just don't detect anything not working right in terms of how the engine is running.
I think it is up to you, but it looks like they have gone over the car, the ECU, codes, etc. and replaced parts to no avail. Do you really want them to keep tinkering with your car, if there is no driveability problem?
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
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Senior Member
Joined: Oct 2005
Posts: 387
Likes: 0
From: East Bay, CA
MB w204 C300 Sport, Audi B7 A4 2.0TQ, Porsche Cayman 981
I looked at what the needle was doing on my car....completely still. (I have 30k on the clock) After acceleration, Park, Neutral, etc. It doesn't bounce around like the video shows.
I have a few theories: bad O2 sensor, mass air flow sensor, or some other sensor along the exhaust system.
Another theory is that your car may be brand new - and it may still be in it's breaking-in stage.
Something is compensating by putting more fuel or air - result is a slight increase in RPM, which is what you are seeing.
How many miles are on your car? And which Northern California dealer did you work with?
...Doh! Just read that you have 12k on your car. So my guess is that its a bad sensor.
I have a few theories: bad O2 sensor, mass air flow sensor, or some other sensor along the exhaust system.
Another theory is that your car may be brand new - and it may still be in it's breaking-in stage.
Something is compensating by putting more fuel or air - result is a slight increase in RPM, which is what you are seeing.
How many miles are on your car? And which Northern California dealer did you work with?
...Doh! Just read that you have 12k on your car. So my guess is that its a bad sensor.
Last edited by itcrashed; Mar 16, 2010 at 06:45 PM.
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
I looked at what the needle was doing on my car....completely still. (I have 30k on the clock) After acceleration, Park, Neutral, etc. It doesn't bounce around like the video shows.
I have a few theories: bad O2 sensor, mass air flow sensor, or some other sensor along the exhaust system.
Another theory is that your car may be brand new - and it may still be in it's breaking-in stage.
Something is compensating by putting more fuel or air - result is a slight increase in RPM, which is what you are seeing.
How many miles are on your car? And which Northern California dealer did you work with?
...Doh! Just read that you have 12k on your car. So my guess is that its a bad sensor.
I have a few theories: bad O2 sensor, mass air flow sensor, or some other sensor along the exhaust system.
Another theory is that your car may be brand new - and it may still be in it's breaking-in stage.
Something is compensating by putting more fuel or air - result is a slight increase in RPM, which is what you are seeing.
How many miles are on your car? And which Northern California dealer did you work with?
...Doh! Just read that you have 12k on your car. So my guess is that its a bad sensor.
Last edited by charliele729; Mar 16, 2010 at 07:23 PM.
Newbie
Joined: Jun 2013
Posts: 6
Likes: 0
C300 Avantgarde
After 3 years, Looks like Mercedes has not rid the problem.
I am having the same issue on my brand new 2013 C300.
During steady drives, the rpm would play up and down.
Also when you step on the throttle lightly and then release, and then step again lightly,
I notice that the rpm needle is climbing up but its very choppy.
Seems like it is out of breath or surging if you call it.
I never experience this kind of issue in my life, whats worse this is a brand new car.
I am still waiting for the dealer response on this issue.
I am having the same issue on my brand new 2013 C300.
During steady drives, the rpm would play up and down.
Also when you step on the throttle lightly and then release, and then step again lightly,
I notice that the rpm needle is climbing up but its very choppy.
Seems like it is out of breath or surging if you call it.
I never experience this kind of issue in my life, whats worse this is a brand new car.
I am still waiting for the dealer response on this issue.
