Ash Pat

Dear MB World People,

I recently bought a 2001 MB S600 W220 engine vehicle. The vehicle is misfiring in the following cylinders according to the Mercedes Star diagnostic:

Passenger side 3 cylinders and Drivers side 5 cylinders are misfiring.

I have done the following to rectify:

1. Added fuel cleaning additive to the fuel, and then put in Shell Hi Octane fuel as the previous owner was using cheap fuel.
2. Then had the car fully serviced and oil changed to Mobile 1 oil.
3. Changed the MASS airflow sensor
4. Changed all 24 Spark Plugs to Iridium OEM NGK ones.
5. Changed the Voltage convertor.

All parts were Mercedes original.

Having done all of the above, the misfiring persists and the car does not drive, it just dumps the fuel.

To Note: When I changed the Spark plugs, many of them were oil covered.

Anybody have any idea what I can do next.
Your help and advice will be much appreciated
Many Thanks.

vettebk

Sorry, I mis-read your other post. Iread it that you had misfire in cylnder 3 and 5. So I said one coil pack.

Now I re-read and it is 3 misfires on one side and 2 on the other. You need both coil packs. Expensive problem.

BenzNinja

iTrader: (4)

still looking for failing voltage converters
if you still have the old one, I would appreciate if you would donate it to the DIY project
postage is payed
https://mbworld.org/forums/m275-v12-...r-upgrade.html

DaleB

Were the plugs just a little oily, or heavily oil fouled? Coil packs and voltage converters aren’t the only things that can cause misfires. Fouled plugs can do the same, and if you’re seeing oil fouled plugs then that oil has to be coming from somewhere.