2017 c63 random misfires

[griffix63]

Hi all, first off I'd like to say yes I've searched, and this forum has provided lots of useful info in the past, but can't find the answer to my specific problem this time, and secondly I WILL PROMISE to update you all when I finally find the faults that is bugging the life out of me so that it helps anyone else with the same issue in future...



Now My Problem, please help if you can:- The car is a stock 2017 C63 AMG with roughly 20k miles. I recently noticed that cylinders 1, 2, 3, 4 from bank 1 misfires.



I started by replacing the all spark plugs for all 8 cylinders, ignition coils and eventually Fuel injector (nozzle), i took off the air cleaners, disconnected the o2 sensors, it still complained misfires from the same bank 1....



When I drove it, to my surprise it drives well till I push it above 5000rpm, I got back the shaking got worse and put an icarsoft MBII scanner on it, and it showed the following codes:-

'Random Misfire'

'Misfire Cylinder 1 Detected'

'Misfire Cylinder 2 Detected'

'Misfire Cylinder 4 Detected'

'Misfire Cylinder 3 Detected'



Please note, all of these misfires are on bank 1 only (the right hand bank).



Since the fault only occured on the right hand bank, I decided to swap everything (in stages) i.e. Fuel injectors, coil packs, etc from right to left , to see if the fault moves, but the fault is STILL on the right hand bank.



Below is a list of things I have tried so far, and I am at a complete loss, so if you can come up with any help, it would be greatly appreciated:-

1) New spark plugs

2) Fuel Injectors swapped from between bank 1 and bank 2

3) Coil packs swapped from between bank 1 and bank 2

4) Ran car with Mass Air Meters and 02 sensor disconnected, made no difference
I am out of ideas at this point.


Thanks in advance for your help.

 

[Larkone]

What does STAR say? - if you have not had it on a STAR machine to diagnose then this is the next best thing if you are going to randomly throw parts at it

 

[Dodipops]

Seems strange to be just one bank.
That would indicate to me maybe an internal issue.
Normally a wiring fault to a coil or injector would also throw an additional code.

Might be worth doing a compression test just to see if there’s a discrepancy between banks.

 

[Jobsworth]

Check for blocked catalyst on that bank. Classic for high rpm misfires on one bank

 

[griffix63]

Update: I noticed while driving, using a star scanner the misfiring cylinders (1, 2 & 3) trouble codes changes from “current” to “stored” then back to “current” when the car comes to a stop.

Sometimes the check engine light disappears then reappears when I put the car on park.

It seems like bank 1 only works when the car is being driven then stops working when it’s not on drive.

What does STAR say? - if you have not had it on a STAR machine to diagnose then this is the next best thing if you are going to randomly throw parts at it View attachment 125492

 

[Larkone]

Update: I noticed while driving, using a star scanner the misfiring cylinders (1, 2 & 3) trouble codes ??????????? changes from “current” to “stored” then back to “current” when the car comes to a stop.

Sometimes the check engine light disappears then reappears when I put the car on park.

It seems like bank 1 only works when the car is being driven then stops working when it’s not on drive.

 

[GayanC63S]

Update: I noticed while driving, using a star scanner the misfiring cylinders (1, 2 & 3) trouble codes changes from “current” to “stored” then back to “current” when the car comes to a stop.

Sometimes the check engine light disappears then reappears when I put the car on park.

It seems like bank 1 only works when the car is being driven then stops working when it’s not on drive.

Hi
What was the reason. How did you get it sorted. I have exactly the same situation and I’m desperately looking for answers. Kindly help me