Misfiring M157
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2013 Mercedes CLS63
Misfiring M157
Hey guys, I have a 2013 cls63 and was told to post this here for more traffic in the thread, so for the past month and a half i’ve been having an issue with my car where the car drives normal but if i floor it, I start losing power and the car’s fuel pressure starts to drop for a few split seconds which causes misfiring which then ecu reads and puts the car into limp mode, but sometimes it doesn’t and the car continues to misfire and shake intensely, but with a quick restart to the engine everything returns to nornal, even if its really quick like just turn off and turn on the engine while coasting in neutral and everything returns to normal till I floor it again and the same cycle happens, now that i’ve explained what happens… let me tell you what i’ve done so far to try and fix this problem, so I took my car to my local amg specialized workshop and had the car diagnosed and they claimed it to be the LPFP finally giving up after 12 years since the car left the factory… so i said fine and had them replace it with a new OEM LPFP which was not cheap at all… so i take the car out for a spin and everything seems to be back to normal, till I get on the highway and decide to test the car there where the problem happens again… now at that point i notice that the issue starts when the car is under load and at higher speeds, it rarely ever happens on 2nd gear but always at 3rd gear or higher… anyways i return to the workshop and explain to them the issue is still there, the mechanic then tells me to keep the car there for a few days till they can really figure out why its still happening… so about 3 days later they call me and tell me that they’ve checked the fuel rails and injectors and found them to be in good condition and working properly but when they were checking the HPFP’s in the engine bay they noticed that the passenger side HPFP was not working at all which they then proceeded to replace it with a OEM bosch HPFP which then they told me to come pick up the car and test drive it, which i then did and still had the issue occur like stated above, now the thing is… before replacing the HPFP, when i would turn the ignition on which primes the fuel system, it would start at 1500psi and then slowly drop down and would not hold the 1500… and after they replaced it, it would hold 1500psi and stay in that range or increase a little which would indicate that there was an issue with the HPFP before, anyways so back to where we were… I test drove the car and still the same issue persisted so i take the car back to the workshop and then they say it could be a faulty fuel pressure sensor which is misreading the fuel pressure when its at full throttle and causing the ecu to get confused at discrepancies in the data it’s receiving, so i change the fuel sensor and still have the same issues… so now im just really tired of trying to fix this problem and honestly just losing motivation to even continue pursuing to fix this issue because i’ve spent so much money on parts and labor and still haven’t resolved the problem… (note: spark plugs were changed and are brand new) so if anyone might have any idea as to what could be causing this and what the solution is… I’d really appreciate any suggestions and help, thank you all honestly cause it’s been really stressful and saddening not being able to enjoy my car fully… thank you.
Please ask me questions to narrow down the issue.
Please ask me questions to narrow down the issue.
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Joined: Mar 2025
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Well, you're getting close. Unfortunately we still need data to determine what's still going on considering some things have changed. SO; if you can get a hold of live data or freeze frame during MIL illumination (if present), that would be fantastic. New parts aside this is a must.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
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2013 Mercedes CLS63
Well, you're getting close. Unfortunately we still need data to determine what's still going on considering some things have changed. SO; if you can get a hold of live data or freeze frame during MIL illumination (if present), that would be fantastic. New parts aside this is a must.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
I also want note that I recently changed coils and plugs with ngk iridium high performance plugs, also my car is stage 2 tuned so its got downpipes and intakes, also want to mention that my car doesn’t reach full boost for whatever reason, after my stage 2 tune it would go past 18psi but now ever since i got the issue it won’t go higher than 12psi.
Last edited by xZapan; Apr 1, 2025 at 03:07 AM.
Thread Starter
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2013 Mercedes CLS63
Well, you're getting close. Unfortunately we still need data to determine what's still going on considering some things have changed. SO; if you can get a hold of live data or freeze frame during MIL illumination (if present), that would be fantastic. New parts aside this is a must.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
Things I'd be looking at are all air, fuel and ignition related voltages, pressures etc. Following that it could be a harmonic issue causing some noise in the system however I highly doubt it.
here are some logs I recorded, you can see that when im at full throttle fuel pressure dramatically drops but as soon as i let off it returns to the normal threshold, even at half throttle it maintains pressure
Last edited by xZapan; Apr 1, 2025 at 03:15 AM.
Super Member
Joined: Oct 2020
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From: ILLINOIS
2014 E63S
Is your intercooler pump working? 60 celsius is about 140* F, that is way to high and will cause the car to pull massive timing to save itself
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2013 Mercedes CLS63
Yeah it is, it’s just that it’s quite hot where I live, and the stainless steel intake doesn’t quite help with that cause it heat soaks so im planning on installing the oem intakes back.
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14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
Your shop is not competent or wants to gouge you without doing a proper diagnosis.
What you're describing suspiciously sounds like failing camshaft magnetic adjusters. Often when they are going out, it cuts fuel exactly as you're describing and throw multiple codes including fuel lean codes because the car was at WOT when also being thrown into limp mode because of the throttle position. Had they bothered to do a proper diagnostic of the sensor values key on engine on, they would have notice a variance between the 4 sensors.
Common issue. Check the plug ends for oil wicking. Replace all 4 sensors if good and add pigtail extensions. For additional insurance, and due to ease and common near simultaneous failure, I also will recommend replacing the cam position sensors with pig tail extensions as well assuming no oil wicking is present.
What you're describing suspiciously sounds like failing camshaft magnetic adjusters. Often when they are going out, it cuts fuel exactly as you're describing and throw multiple codes including fuel lean codes because the car was at WOT when also being thrown into limp mode because of the throttle position. Had they bothered to do a proper diagnostic of the sensor values key on engine on, they would have notice a variance between the 4 sensors.
Common issue. Check the plug ends for oil wicking. Replace all 4 sensors if good and add pigtail extensions. For additional insurance, and due to ease and common near simultaneous failure, I also will recommend replacing the cam position sensors with pig tail extensions as well assuming no oil wicking is present.
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2013 Mercedes CLS63
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From: ILLINOIS
2014 E63S
Thread Starter
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2013 Mercedes CLS63
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14 E63, 05 E55, 03 Evo 8, 08 F250, 06 R6R, 92 Talon TSI, and instability
https://mbworld.org/forums/w212-amg/...sors-leak.html
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E320
Since you’ve already tackled some of the common culprits, it might be worth considering a few other possibilities. Have you checked the ignition coils and spark plugs? Sometimes, a faulty coil can lead to misfires, and they can be tricky to diagnose. Additionally, it might be helpful to look into the fuel injectors, as clogged or malfunctioning injectors can also cause misfiring issues. I would get a good scanner either star or youcanic pro scanner and pull any diagnostic trouble codes and post them here. It could also be beneficial to check for any vacuum leaks or issues with the intake system, as these can affect engine performance as well. Keep us posted on what you find out, and hopefully, we can help you get this sorted!
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Since you’ve already tackled some of the common culprits, it might be worth considering a few other possibilities. Have you checked the ignition coils and spark plugs? Sometimes, a faulty coil can lead to misfires, and they can be tricky to diagnose. Additionally, it might be helpful to look into the fuel injectors, as clogged or malfunctioning injectors can also cause misfiring issues. I would get a good scanner either star or youcanic pro scanner and pull any diagnostic trouble codes and post them here. It could also be beneficial to check for any vacuum leaks or issues with the intake system, as these can affect engine performance as well. Keep us posted on what you find out, and hopefully, we can help you get this sorted!
