C63s acceleration issue
Thread Starter
Newbie
Joined: Feb 2024
Posts: 3
Likes: 1
2017 C63s
C63s acceleration issue
Hi there, I am new to the mbworld. I have a pre-owned 2017 C63S, and my car is facing some acceleration issues. I hope that someone can provide some suggestions regarding the issue.
After the car comes to a complete stop, sometimes when I press the throttle, the RPM spikes to two or three thousand before there is any power, while at other times the response is very prompt. After coming to a complete stop, the car takes a few seconds after releasing the brake to start moving at low speed, and then the throttle response becomes very prompt again after starting the low-speed movement. The same behaviour happens in both forward and reverse gears.
The dealer said there was a misfire, and they have replaced spark plugs, coils and a fuel injector of the misfire cylinder, but there has been no change. The engine light on the car is not on, and there are no obvious fault codes, only one error code that the dealer told me was the P140473, which should be related to the exhaust valve, but I have seen in other posts that this fault code does not affect performance.
I am wondering if someone can suggest what needs to be checked next step? After doing some investigations online, it seems that the manifold absolute pressure sensors or oil pump can cause this issue. Thanks everyone in advance.
After the car comes to a complete stop, sometimes when I press the throttle, the RPM spikes to two or three thousand before there is any power, while at other times the response is very prompt. After coming to a complete stop, the car takes a few seconds after releasing the brake to start moving at low speed, and then the throttle response becomes very prompt again after starting the low-speed movement. The same behaviour happens in both forward and reverse gears.
The dealer said there was a misfire, and they have replaced spark plugs, coils and a fuel injector of the misfire cylinder, but there has been no change. The engine light on the car is not on, and there are no obvious fault codes, only one error code that the dealer told me was the P140473, which should be related to the exhaust valve, but I have seen in other posts that this fault code does not affect performance.
I am wondering if someone can suggest what needs to be checked next step? After doing some investigations online, it seems that the manifold absolute pressure sensors or oil pump can cause this issue. Thanks everyone in advance.
Out Of Control!!
Joined: Nov 2018
Posts: 11,451
Likes: 5,352
From: San Francisco Bay Area
2019 C63CS
Malfunctioning exhaust valves will cause limp mode. It's kinda hard to discern from your description if you are describing clutch slip in the transmission or the engine not making expected torque/power, but the fact that you have a fault code for the exhaust valves points to limp mode.
Thread Starter
Newbie
Joined: Feb 2024
Posts: 3
Likes: 1
2017 C63s
Thanks @superswiss . I hope that is not the clutch slip or the engine issue, as the throttle seems to work normally once the car starts running. I will ask the dealer to look into the exhaust valves first.
Member
Joined: Oct 2020
Posts: 124
Likes: 21
C63s
I'm sure you ruled this out but is the rpm "slip" when the engine is cold? And when the engine warms up the throttle response is more immediate?
My car does something that I could describe similarly to what you said but idk if its the same as what you're describing. Anyway it's normal with our clutch. On a cold engine and trans (the colder it is the more prominent). The engine rpm rises to around 1800-2300 (I'm completely stationary) before the car finally drops the clutch and I slowly take off. It will even sit there in that rpm range continuously until you push the throttle over the threshold it has to hit. There are times I've been sitting there for 3-5s with the engine cranking just waiting to start moving. Once the car warms up this behavior goes away/becomes nearly imperceptible. Our wet clutch feels closer to a manual trans than to a torque converter auto. I think of it as a driver slipping in a clutch with cold (and not very grabby due to temp) friction material.
My car does something that I could describe similarly to what you said but idk if its the same as what you're describing. Anyway it's normal with our clutch. On a cold engine and trans (the colder it is the more prominent). The engine rpm rises to around 1800-2300 (I'm completely stationary) before the car finally drops the clutch and I slowly take off. It will even sit there in that rpm range continuously until you push the throttle over the threshold it has to hit. There are times I've been sitting there for 3-5s with the engine cranking just waiting to start moving. Once the car warms up this behavior goes away/becomes nearly imperceptible. Our wet clutch feels closer to a manual trans than to a torque converter auto. I think of it as a driver slipping in a clutch with cold (and not very grabby due to temp) friction material.
Last edited by '1663s; Feb 7, 2024 at 07:53 AM.
Thread Starter
Newbie
Joined: Feb 2024
Posts: 3
Likes: 1
2017 C63s
Thanks guys. I changed the transmission fluid two years ago when the odometer was around 27,000 km, and now it's at 33,000 km. The problem was already present before changing the transmission fluid and filter, but it wasn't that frequent. It seems that my problem isn't affected by the engine temperature. Sometimes the symptom doesn't occur at all from a cold start, and sometimes it persists even as the temperature rises.
One thing I've noticed is that when the symptom occurs and I release the brake to let the car start moving at low speed, the idle sound (not sure if it is from the exhaust) seems to get louder, but the RPM is steady. And when the car comes to a full stop, the sound becomes lower.
I asked the dealer advisor to send me the report yesterday, and it is actually showing three faulty codes:
```
P140471 (S - STORED) Exhaust flap 2 has a malfunction. The actuator is blocked.
P140472 (A - CURRENT) Exhaust flap 2 has a malfunction. The actuator does not close.
P002177 (S - STORED) The position of the intake camshaft (cylinder bank 2) deviates from the specified value. The commanded position cannot be reached.
```
I think the car might be experiencing some airflow issues. I think superswiss is probably right that these codes need to be addressed first. I'm going to a new dealership tomorrow since the previous advisor doesn't seem to be familiar with the car. I'll keep you posted.
One thing I've noticed is that when the symptom occurs and I release the brake to let the car start moving at low speed, the idle sound (not sure if it is from the exhaust) seems to get louder, but the RPM is steady. And when the car comes to a full stop, the sound becomes lower.
I asked the dealer advisor to send me the report yesterday, and it is actually showing three faulty codes:
```
P140471 (S - STORED) Exhaust flap 2 has a malfunction. The actuator is blocked.
P140472 (A - CURRENT) Exhaust flap 2 has a malfunction. The actuator does not close.
P002177 (S - STORED) The position of the intake camshaft (cylinder bank 2) deviates from the specified value. The commanded position cannot be reached.
```
I think the car might be experiencing some airflow issues. I think superswiss is probably right that these codes need to be addressed first. I'm going to a new dealership tomorrow since the previous advisor doesn't seem to be familiar with the car. I'll keep you posted.
Member
Joined: Feb 2022
Posts: 120
Likes: 35
C63s
I'm sure you ruled this out but is the rpm "slip" when the engine is cold? And when the engine warms up the throttle response is more immediate?
My car does something that I could describe similarly to what you said but idk if its the same as what you're describing. Anyway it's normal with our clutch. On a cold engine and trans (the colder it is the more prominent). The engine rpm rises to around 1800-2300 (I'm completely stationary) before the car finally drops the clutch and I slowly take off. It will even sit there in that rpm range continuously until you push the throttle over the threshold it has to hit. There are times I've been sitting there for 3-5s with the engine cranking just waiting to start moving. Once the car warms up this behavior goes away/becomes nearly imperceptible. Our wet clutch feels closer to a manual trans than to a torque converter auto. I think of it as a driver slipping in a clutch with cold (and not very grabby due to temp) friction material.
My car does something that I could describe similarly to what you said but idk if its the same as what you're describing. Anyway it's normal with our clutch. On a cold engine and trans (the colder it is the more prominent). The engine rpm rises to around 1800-2300 (I'm completely stationary) before the car finally drops the clutch and I slowly take off. It will even sit there in that rpm range continuously until you push the throttle over the threshold it has to hit. There are times I've been sitting there for 3-5s with the engine cranking just waiting to start moving. Once the car warms up this behavior goes away/becomes nearly imperceptible. Our wet clutch feels closer to a manual trans than to a torque converter auto. I think of it as a driver slipping in a clutch with cold (and not very grabby due to temp) friction material.
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Member
Joined: Jan 2022
Posts: 159
Likes: 42
From: San Diego,CA
2021 AMG C63S, 2008 C300
Thanks guys. I changed the transmission fluid two years ago when the odometer was around 27,000 km, and now it's at 33,000 km. The problem was already present before changing the transmission fluid and filter, but it wasn't that frequent. It seems that my problem isn't affected by the engine temperature. Sometimes the symptom doesn't occur at all from a cold start, and sometimes it persists even as the temperature rises.
One thing I've noticed is that when the symptom occurs and I release the brake to let the car start moving at low speed, the idle sound (not sure if it is from the exhaust) seems to get louder, but the RPM is steady. And when the car comes to a full stop, the sound becomes lower.
I asked the dealer advisor to send me the report yesterday, and it is actually showing three faulty codes:
```
P140471 (S - STORED) Exhaust flap 2 has a malfunction. The actuator is blocked.
P140472 (A - CURRENT) Exhaust flap 2 has a malfunction. The actuator does not close.
P002177 (S - STORED) The position of the intake camshaft (cylinder bank 2) deviates from the specified value. The commanded position cannot be reached.
```
I think the car might be experiencing some airflow issues. I think superswiss is probably right that these codes need to be addressed first. I'm going to a new dealership tomorrow since the previous advisor doesn't seem to be familiar with the car. I'll keep you posted.
One thing I've noticed is that when the symptom occurs and I release the brake to let the car start moving at low speed, the idle sound (not sure if it is from the exhaust) seems to get louder, but the RPM is steady. And when the car comes to a full stop, the sound becomes lower.
I asked the dealer advisor to send me the report yesterday, and it is actually showing three faulty codes:
```
P140471 (S - STORED) Exhaust flap 2 has a malfunction. The actuator is blocked.
P140472 (A - CURRENT) Exhaust flap 2 has a malfunction. The actuator does not close.
P002177 (S - STORED) The position of the intake camshaft (cylinder bank 2) deviates from the specified value. The commanded position cannot be reached.
```
I think the car might be experiencing some airflow issues. I think superswiss is probably right that these codes need to be addressed first. I'm going to a new dealership tomorrow since the previous advisor doesn't seem to be familiar with the car. I'll keep you posted.
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Out Of Control!!
Joined: Nov 2018
Posts: 11,451
Likes: 5,352
From: San Francisco Bay Area
2019 C63CS
Member
Joined: Jan 2022
Posts: 159
Likes: 42
From: San Diego,CA
2021 AMG C63S, 2008 C300
Out Of Control!!
Joined: Nov 2018
Posts: 11,451
Likes: 5,352
From: San Francisco Bay Area
2019 C63CS
Before I reset adaptations with Xentry this was happening a couple times a week. After I reset and did a “re-learn” road test it seemed to improve but still happens here and there. You must have gotten a better version than mine lol. Or maybe the first year of the FL 9G is different and they changed something in 21?
Member
Joined: Jan 2022
Posts: 159
Likes: 42
From: San Diego,CA
2021 AMG C63S, 2008 C300
I've mentioned this before. I do all my spirited driving in manual mode. In fact I only use the automatic modes for moderate driving around town, in traffic or if I'm just cruising along with DISTRONIC engaged. I do all other driving in manual mode. My individual mode is configured to put the transmission in M, and it's the mode I use on the highway and open roads. My theory has always been that if you mix driving styles, the adaptations will never quite learn how you want to drive.
Out Of Control!!
Joined: Nov 2018
Posts: 11,451
Likes: 5,352
From: San Francisco Bay Area
2019 C63CS
Do you prefer Race or Sport+ in manual? I usually alternate between the two. I noticed if I use sport mode around town that’s when I get the occasional wet clutch issues. I hardly ever use comfort no more. I hate going 40 mph and being in 9th gear. It tends to lug the engine a lot in comfort.
Can't say my engine lugs in Comfort mode. In fact the transmission downshifts the moment I let off the throttle and start slowing down, so it's pretty much always in the right gear. It often drops multiple gears, too. Like jumping straight down from 9 to 7, or 5 to 3. It really has adapted well to my around town driving.
EDIT: When I'm in Race mode I also put ESP in Sport Handling, which activates the AMG DYNAMICS Master mode making the handling so much more neutral and controllable for drifting. The locking differential really shines in Master mode, too.
Last edited by superswiss; Feb 10, 2024 at 03:12 AM.
