RPM Gauge Question
Thread Starter
Senior Member
Joined: Feb 2010
Posts: 295
Likes: 0
From: Seattle, WA
2005 C55 AMG
RPM Gauge Question
Hi All-
I've owned my C55 for about a month and a half now, and love it. It has just 22,000 miles, and seems to be in excellent shape. However, I've noticed that during cruising at a fairly constant speed (in all modes, C, S, M) the RPM's will fluctuate constantly by a few miniscule RPM. I'm not sure if there is something wrong with the gauge, or the engine. Has anyone else noticed this? No other car I've had does this. Perhaps this is normal for the car, but I'm unsure at this point. Could this be a loose belt of some sort?
I've owned my C55 for about a month and a half now, and love it. It has just 22,000 miles, and seems to be in excellent shape. However, I've noticed that during cruising at a fairly constant speed (in all modes, C, S, M) the RPM's will fluctuate constantly by a few miniscule RPM. I'm not sure if there is something wrong with the gauge, or the engine. Has anyone else noticed this? No other car I've had does this. Perhaps this is normal for the car, but I'm unsure at this point. Could this be a loose belt of some sort?
Thread Starter
Senior Member
Joined: Feb 2010
Posts: 295
Likes: 0
From: Seattle, WA
2005 C55 AMG
Very observant 
Almost too observant!
Another symptom that I've been worried about is when I'm in either S or C mode, and begin to accelerate, the rpms will actually drop prior to rising with speed. This has got to be the software, which leads me to my next question, how to reset?
Almost too observant! Another symptom that I've been worried about is when I'm in either S or C mode, and begin to accelerate, the rpms will actually drop prior to rising with speed. This has got to be the software, which leads me to my next question, how to reset?
Super Member
Joined: Jun 2008
Posts: 855
Likes: 2
2010 C63
This is normal when you're starting off from a stop, it's basically doing the same thing a clutch would do. Rpm's drop as the torque converter locks up and then rpm's rise as you accelerate. I find this to be annoying at times which is why I drive in S mode unless I'm really babying her around town.
mike
mike
Very observant Almost too observant!
Another symptom that I've been worried about is when I'm in either S or C mode, and begin to accelerate, the rpms will actually drop prior to rising with speed. This has got to be the software, which leads me to my next question, how to reset?
Almost too observant! Another symptom that I've been worried about is when I'm in either S or C mode, and begin to accelerate, the rpms will actually drop prior to rising with speed. This has got to be the software, which leads me to my next question, how to reset?
