koifysh

This started on sunday. Every time I drive for about 30 minutes and go wot, I start getting flashing engine light plus rough acceleration and idle. Definitely a misfire as the car is shaking. I installed new spark plugs in September. So could it be the coils? For those that had this problem in the past. If it’s really my ignition coils. Should I go ahead and replace all the spark plugs too? They’re only 3 month old

https://youtube.com/shorts/jdeCEJgjH1I?si=kd-nvg_IkSs46p0q

https://youtube.com/shorts/jdeCEJgjH1I?si=kd-nvg_IkSs46p0q

untamedd

no need to change your spark plugs if you just changed them 3 months ago

i had a similar situation where i had changed my spark plugs but after about 6-7 months my car started misfiring. Had it checked, one of the coils was going bad but i just replaced them all and all good now

koifysh

i got some help from the awesome people at ptg. Got these following codes:



P074286
P061B00
U042600

no idea what it means

koifysh

i got some help from the awesome people at ptg. Got these following codes:



P074286
P061B00
U042600

no idea what it means

noremaC

How did you pull these codes?

progonat

Based on the symptoms you've described and the diagnostic trouble codes (DTCs) you've provided, it does sound like you're experiencing an engine misfire. The flashing engine light, rough acceleration, and idle, along with the shaking, are classic signs of this issue. Let's break down what these codes might indicate:

1. P074286: This code isn't standard in the OBD-II code format, which typically consists of a letter followed by four digits. It's possible there might be a typo in this code. If it's meant to be P0742, it would refer to a problem with the torque converter clutch circuit, which could affect driving performance but is less likely to cause a misfire.
   
2. P061B00: This code suggests an internal control module torque calculation performance issue. This might be related to the engine control module (ECM) and could be a sign of problems with the vehicle's computer system or software. This code might not directly point to a misfire but could indicate issues with engine management.
   
3. U042600: This is a communication code, typically indicating a lost communication with a specific module. This could be related to various systems in the vehicle, and diagnosing this will likely require professional equipment and expertise.
   

Given that you've recently changed the spark plugs, they are less likely to be the issue, especially if they were correctly installed and are the right type for your vehicle. However, ignition coils could indeed be the culprit, as they are crucial in providing the spark to ignite the fuel-air mixture in the cylinders. If one or more coils are failing, it can lead to misfiring.

koifysh

from a verstand from ptg when I did my tcu tune

koifysh

[QUOTE=progonat;8889055]Based on the symptoms you've described and the diagnostic trouble codes (DTCs) you've provided, it does sound like you're experiencing an engine misfire. The flashing engine light, rough acceleration, and idle, along with the shaking, are classic signs of this issue. Let's break down what these codes might indicate:

1. P074286: This code isn't standard in the OBD-II code format, which typically consists of a letter followed by four digits. It's possible there might be a typo in this code. If it's meant to be P0742, it would refer to a problem with the torque converter clutch circuit, which could affect driving performance but is less likely to cause a misfire.
   
2. P061B00: This code suggests an internal control module torque calculation performance issue. This might be related to the engine control module (ECM) and could be a sign of problems with the vehicle's computer system or software. This code might not directly point to a misfire but could indicate issues with engine management.
   
3. U042600: This is a communication code, typically indicating a lost communication with a specific module. This could be related to various systems in the vehicle, and diagnosing this will likely require professional equipment and expertise.
   

Given that you've recently changed the spark plugs, they are less likely to be the issue, especially if they were correctly installed and are the right type for your vehicle. However, ignition coils could indeed be the culprit, as they are crucial in providing the spark to ignite the fuel-air mixture in the cylinders. If one or more coils are failing, it can lead to misfiring.[/QUOTE

is water spill in the trunk also a culprit?

noremaC

I can help you read the codes. When you are in the Verstand ECU menu, run the "Read DTC" option and send the the full code lines over to me. They should be in German.

koifysh

this is what I got in the ecu menu when reading dtc

koifysh

Finally got my coils from mercteil last week for $180 each. 2 week for delivery. Installed it today after half an hour of wiggling them out because of the god damn fuel line. Drives soooo smoothhh & the power. I can break traction 20% throttle. Thank god it wasn’t fuel pump or any other bs lol.

koifysh

One more question for you guys. Recently i’ve been noticing the rpm fluctuate a little bit when in idling & the car would have a light shake. It would go away for 15-20 seconds then come back and repeat. Same thing when coming to a stop. The rpm would rev up then back down, sometimes a little and other times till 1700 rpm. No codes or check engine light. Since coils and new spark plugs are out of the way. I’m speculating that its a vacuum leak or map sensor. My question is, how many vacuum valve are in the engine and where are they located? I’m going to try and replace them along with all the MAP sensor

SJGetsome

I had a similar symptom a while back and ended up checking my spark plugs and found one of them had failed. The ceramic was loose and dropped down over the electrode. It caused an intermittent misfire with no code most of the time. It may have happened to you.

koifysh

i already change out both my coils and plugs. No more misfure and rough idle. Just these weird pulsing and rpm fluctuations every 15 second when cold & less so when warm. But its only on idle and when coming to a stop the rpm would go up a bit then back down

koifysh

Another weird problem. Every time I park the car then turn it back on, put it in reverse then to drive and let it roll by itself (without touching the throttle) the rpm would surge up and down. This is reproducible no matter if cold or warm. Bad throttle sensor?

note: this only happens if I turn the car off, then turn back on and put it in reverse then drive and let the car roll. Back when I first took delivery. I remembered during cold start when I give it 0.5% throttle (a very light touch) it would do the same thing. Never thought anything of it until now

mokawop

I had the same issues as you on my last c63s. For me replacing my purge valves solved the issue. They were also very loud so I resolved two things with one part. Hope this helps.

koifysh

i did change my purge valve. I think i found the cause. Looks like a small leak over time. I tightened that part a little and it help a lot with the problem. Do you know the name of this part?

mokawop

Sorry which part are you referring to? The connection closest to the camera? There’s alot of leakable connections in the photo haha.

koifysh

This part, closest to the photo. Btw, do you know how many vacuum valves are there in this engine?


this part

4npower

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