2012 C63 rough idle + shaking
09-13-2016, 12:37 PM
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12 C63 Coupe
2012 C63 rough idle + shaking
hey guys I've had my car for about a month now, 2012 c63 coupe with 52k miles and about a week ago i backed my car out of the garage and sat there for about 5-10 mins setting up my phone with the car. Afterwards i drove off and noticed the car started shaking violently and bucking and noticed the CEL was blinking (misfiring) i quickly turned around parked in my driveway turned off the car then restarted and the car was perfectly fine and drove normal with no CEL, also plugged in my ODB2 reader and there were no codes stored. Since then the problem has never came back...
Ever since then i've been really paranoid and i'm not sure if my car is idling rougher or not as fast, responsive, etc etc. I've noticed that some people have had this issue before and just wanted your input. I was thinking about doing coil packs + plugs since i don't know if it's ever been done/replaced also, does your RPM gauge/needle fluctuate a little say when you're cruising on the freeway at a steady speed?
Ever since then i've been really paranoid and i'm not sure if my car is idling rougher or not as fast, responsive, etc etc. I've noticed that some people have had this issue before and just wanted your input. I was thinking about doing coil packs + plugs since i don't know if it's ever been done/replaced also, does your RPM gauge/needle fluctuate a little say when you're cruising on the freeway at a steady speed?
Last edited by itzjonjon69; 09-13-2016 at 08:48 PM.
09-13-2016, 12:41 PM
#2
it's low fuel rail pressure most likely
my car does the same if it's around quarter tank and i get into it, it will blink cell then the car will sound like it's about to blow up and you have to pull over ..restart etc ..then sometimes even if you WOT it there is 0 response ...idk these cars are weird sometimes ..and yes i've replaced the fuel rail + pumps and it still does it ...it's just how these cars are sometimes honestly
buy a ODB2 blue tooth reader and i'm willing to bet thats exactly what you'll see ..is low fuel rail pressure
i doubt it's your plugs ...i've been really busy the last few months and haven't had time to get my plugs done but my car has 110,000KM on original plugs (going in next month) so the plugs don't really crap out right @ 100,000km unless you track a lot
my car does the same if it's around quarter tank and i get into it, it will blink cell then the car will sound like it's about to blow up and you have to pull over ..restart etc ..then sometimes even if you WOT it there is 0 response ...idk these cars are weird sometimes ..and yes i've replaced the fuel rail + pumps and it still does it ...it's just how these cars are sometimes honestly
buy a ODB2 blue tooth reader and i'm willing to bet thats exactly what you'll see ..is low fuel rail pressure
i doubt it's your plugs ...i've been really busy the last few months and haven't had time to get my plugs done but my car has 110,000KM on original plugs (going in next month) so the plugs don't really crap out right @ 100,000km unless you track a lot
Last edited by MJames2; 09-13-2016 at 12:43 PM.
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itzjonjon69 (09-13-2016)
09-13-2016, 12:50 PM
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12 C63 Coupe
it's low fuel rail pressure most likely
my car does the same if it's around quarter tank and i get into it, it will blink cell then the car will sound like it's about to blow up and you have to pull over ..restart etc ..then sometimes even if you WOT it there is 0 response ...idk these cars are weird sometimes ..and yes i've replaced the fuel rail + pumps and it still does it ...it's just how these cars are sometimes honestly
buy a ODB2 blue tooth reader and i'm willing to bet thats exactly what you'll see ..is low fuel rail pressure
i doubt it's your plugs ...i've been really busy the last few months and haven't had time to get my plugs done but my car has 110,000KM on original plugs (going in next month) so the plugs don't really crap out right @ 100,000km unless you track a lot
my car does the same if it's around quarter tank and i get into it, it will blink cell then the car will sound like it's about to blow up and you have to pull over ..restart etc ..then sometimes even if you WOT it there is 0 response ...idk these cars are weird sometimes ..and yes i've replaced the fuel rail + pumps and it still does it ...it's just how these cars are sometimes honestly
buy a ODB2 blue tooth reader and i'm willing to bet thats exactly what you'll see ..is low fuel rail pressure
i doubt it's your plugs ...i've been really busy the last few months and haven't had time to get my plugs done but my car has 110,000KM on original plugs (going in next month) so the plugs don't really crap out right @ 100,000km unless you track a lot
09-13-2016, 01:17 PM
#4
no stored codes? now thats a new one ...what program are you using? i use torque pro ..seems like one of the better ones
09-13-2016, 01:23 PM
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Using bluedriver, the CEL never stayed solid it just kept blinking while i was driving then when i turned off the car and back on there was no CEL or anything.
09-13-2016, 05:56 PM
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
That's funny that AMG would design a car that misfires and fuel starves when the fuel tank is at 1/4 or below. You'd think those engineers would think of that.
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09-13-2016, 07:31 PM
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Last edited by itzjonjon69; 09-13-2016 at 08:48 PM.
09-13-2016, 09:11 PM
#9
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Mine is steady. Start up - higher revs then settles down and is constant at idle.
Sounds just like a little hiccup to me. Understandably that may not sit well but if it drives fine, no CEL, I would just drive it as usual and keep an eye on things.
Sounds just like a little hiccup to me. Understandably that may not sit well but if it drives fine, no CEL, I would just drive it as usual and keep an eye on things.
09-13-2016, 09:16 PM
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09-15-2016, 09:18 PM
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12 C63 Coupe
09-15-2016, 09:37 PM
#13
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Your RPM will fluctuate while maintaining a steady speed to account for wind resistance, grade changes etc... It's normal.
09-15-2016, 09:48 PM
#14
cleared the code, found a gas station 15 or so minutes away chucked 40 bucks in and beat the **** out of it with 0 issues
crazy part is, i can go months without the issue too, then boom one day the car just starts doing it again for a few months, i've had the car since new and this happens every year pretty much for who knows why
could the whole summer / winter gas blend thing cause this possibly?
Last edited by MJames2; 09-15-2016 at 09:54 PM.
09-16-2016, 07:06 AM
#15
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This is probably not going to be an easy fix. But you have to do some logging.
I'm too new to the recent Mercedes world to know what is used here for logging, but in the Subaru world, there is an open source software that lets you use your laptop to do this, via an OBD2 cable.
This type of issue, you need weeks of logging, what happens when the car is fine and what happens when you get the problem. You'd want the engine load, obviously RPM, fuel pressure, speed.
There probably is a fuel pump or fuel pump controller parameter too.
From what I read so far, looks like the M156 at least in the C63 does not have a fuel pressure regulator, it uses the no return lines and the fuel pump controllers to vary the speed, therefore flow of the pumps, therefore the fuel pressure, because it controls the duty cycle of the injectors in the first place.
Now the pumps are cooled by the fuel. When the tank is relatively low, the fuel pump temperature could increase. Is the ECU monitoring this? I don't know. If it does, it needs to be logged.
I'm too new to the recent Mercedes world to know what is used here for logging, but in the Subaru world, there is an open source software that lets you use your laptop to do this, via an OBD2 cable.
This type of issue, you need weeks of logging, what happens when the car is fine and what happens when you get the problem. You'd want the engine load, obviously RPM, fuel pressure, speed.
There probably is a fuel pump or fuel pump controller parameter too.
From what I read so far, looks like the M156 at least in the C63 does not have a fuel pressure regulator, it uses the no return lines and the fuel pump controllers to vary the speed, therefore flow of the pumps, therefore the fuel pressure, because it controls the duty cycle of the injectors in the first place.
Now the pumps are cooled by the fuel. When the tank is relatively low, the fuel pump temperature could increase. Is the ECU monitoring this? I don't know. If it does, it needs to be logged.
Last edited by Vladds; 09-16-2016 at 07:21 AM.
09-17-2016, 01:22 PM
#16
This is probably not going to be an easy fix. But you have to do some logging.
I'm too new to the recent Mercedes world to know what is used here for logging, but in the Subaru world, there is an open source software that lets you use your laptop to do this, via an OBD2 cable.
This type of issue, you need weeks of logging, what happens when the car is fine and what happens when you get the problem. You'd want the engine load, obviously RPM, fuel pressure, speed.
There probably is a fuel pump or fuel pump controller parameter too.
From what I read so far, looks like the M156 at least in the C63 does not have a fuel pressure regulator, it uses the no return lines and the fuel pump controllers to vary the speed, therefore flow of the pumps, therefore the fuel pressure, because it controls the duty cycle of the injectors in the first place.
Now the pumps are cooled by the fuel. When the tank is relatively low, the fuel pump temperature could increase. Is the ECU monitoring this? I don't know. If it does, it needs to be logged.
I'm too new to the recent Mercedes world to know what is used here for logging, but in the Subaru world, there is an open source software that lets you use your laptop to do this, via an OBD2 cable.
This type of issue, you need weeks of logging, what happens when the car is fine and what happens when you get the problem. You'd want the engine load, obviously RPM, fuel pressure, speed.
There probably is a fuel pump or fuel pump controller parameter too.
From what I read so far, looks like the M156 at least in the C63 does not have a fuel pressure regulator, it uses the no return lines and the fuel pump controllers to vary the speed, therefore flow of the pumps, therefore the fuel pressure, because it controls the duty cycle of the injectors in the first place.
Now the pumps are cooled by the fuel. When the tank is relatively low, the fuel pump temperature could increase. Is the ECU monitoring this? I don't know. If it does, it needs to be logged.
pretty sure the ECU doesn't monitor the fuel pump temp, at least i can't find anything in torque pro that shows the fuel pump temp ...that could be one of the issues though, low fuel, hotter pumps, i mean a CPU on a computer without any cooling will over heat very fast so i imagine fuel pumps on a C63 without them being soaked in fuel gets hot very fast
makes total sense because my car legit chokes out and feels like its about to stuff some pistons through the hood. I can WOT the gas pedal to during this and 0 response, let the car sit for a few mins, turn it back on and boom...runs perfect especially after it has some more gas then 1/4 tank
09-17-2016, 02:48 PM
#18
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Have you had the inside of your fuel tank visually inspected? If the symptoms only arise during low fuel situations there might be some "junk" in the tank. Either way worth a look as it sounds like you have exhausted other avenues.
Years ago I had a car with similar symptoms, couldn't figure it out for a long time turned out to be trash in the bottom of the tank.
Years ago I had a car with similar symptoms, couldn't figure it out for a long time turned out to be trash in the bottom of the tank.
09-19-2016, 10:48 PM
#19
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So I had another look at the WIS and this time I found the diagram.
The cars have saddle style tanks, like many other cars. Both pumps are on the right side and rely upon a jet pump (actuated via venturi) to draw fuel from the left part of the saddle.
Now even with this, the diagram is incomplete. In a Subaru there are fuel level senders in both sides of the tank, then the ECU takes the signals from both and decides what the fuel level is.
So, if somehow the venturi syphoning of the fuel from the left to the right does not work and there are level senders on both sides, the ECU will see a big difference between left and right. I can't say what it will show in the dash, maybe the left side?
How about a different idea? the pipe that does the syphoning is partially clogged or dented. It still works, but slow. The left and right eventually equalize, but as you drive, the pump side will starve every now and then.
The cars have saddle style tanks, like many other cars. Both pumps are on the right side and rely upon a jet pump (actuated via venturi) to draw fuel from the left part of the saddle.
Now even with this, the diagram is incomplete. In a Subaru there are fuel level senders in both sides of the tank, then the ECU takes the signals from both and decides what the fuel level is.
So, if somehow the venturi syphoning of the fuel from the left to the right does not work and there are level senders on both sides, the ECU will see a big difference between left and right. I can't say what it will show in the dash, maybe the left side?
How about a different idea? the pipe that does the syphoning is partially clogged or dented. It still works, but slow. The left and right eventually equalize, but as you drive, the pump side will starve every now and then.
09-20-2016, 01:37 AM
#20
Senior Member
Originally Posted by Vladds
So I had another look at the WIS and this time I found the diagram.
The cars have saddle style tanks, like many other cars. Both pumps are on the right side and rely upon a jet pump (actuated via venturi) to draw fuel from the left part of the saddle.
Now even with this, the diagram is incomplete. In a Subaru there are fuel level senders in both sides of the tank, then the ECU takes the signals from both and decides what the fuel level is.
So, if somehow the venturi syphoning of the fuel from the left to the right does not work and there are level senders on both sides, the ECU will see a big difference between left and right. I can't say what it will show in the dash, maybe the left side?
How about a different idea? the pipe that does the syphoning is partially clogged or dented. It still works, but slow. The left and right eventually equalize, but as you drive, the pump side will starve every now and then.
The cars have saddle style tanks, like many other cars. Both pumps are on the right side and rely upon a jet pump (actuated via venturi) to draw fuel from the left part of the saddle.
Now even with this, the diagram is incomplete. In a Subaru there are fuel level senders in both sides of the tank, then the ECU takes the signals from both and decides what the fuel level is.
So, if somehow the venturi syphoning of the fuel from the left to the right does not work and there are level senders on both sides, the ECU will see a big difference between left and right. I can't say what it will show in the dash, maybe the left side?
How about a different idea? the pipe that does the syphoning is partially clogged or dented. It still works, but slow. The left and right eventually equalize, but as you drive, the pump side will starve every now and then.
