medic20102

I have a 2002 cl600 that I had to put 87 octane fuel in it because the 91 was out of service it wound up throwing 8 misfire codes after emptying tank and putting a tank of 91 through it it cleared down to 4 codes that won't go away
I have random misfire and misfire in cylinders 4 5 and 6 if anyone could help I would really appreciate it

medic20102

93 octane I meant

canes85

When was the last time you changes your spark plugs?

Every 5 years of 100,000 which ever comes first.

medic20102

I just bought the car 2 miles ago only has 42000 miles had it diagnosed at dealer when I bought and they said everything was good

medic20102

Months ago*

medic20102

Would it be the plugs??? Cause A Lot More We're Misfiring Before Now Its Just Those 3

medic20102

Any ideas would be really helpful as I don't really wanna pay Mercedes to replace part after part trying to figure it out. Could I be an 02 sensor since it's 4 5 and 6 and I read somewhere the 4 02 sensors each go to 3 cylinders. And if it could be how do I check and where is the 02 sensor located

Speedriven1

What are the codes? Could be 1 of 4 things. Spark plugs are fouled, ignition module is faulty, coil pack is faulty, or could have a breather issue caused by oil not draining quick enough in the heads(rare issue)

biker349

i go for ignition module, or coil pack. mine had a code 300 i believe and was misfiring on random cylinders. turned out to be ignition module and accelerator pedal. coil packs were good to go.

jeffjaguar4

I replaced one coil pack and problem went away, a couple of months later the other coil pack began misfiring, changed that and it was ok, About 6 monthes later I was driving and the car just stalled out, my mechanic came out and replaced a fuse to the ignition module (square box located on the top center of engine under plastic cover $450.00) Had new module installed and the car now runs better than it ever did. The module was probably the problem all along it was not sending the correct voltage to the coils, so over time it probably ruined the coils and it didn't run like a V12 should run( I've had other V12's) The car now runs like a V12 should smooth and strong. I hope this helped someone out there.

pmercury

iTrader: (2)

thank you but this has been discussed 1000 times in the forum
I am not unkind and don't take this as a aggression but
next time please search before creating a useless thread

cause for misfire are oil leak, plugs, coil pack or transformer
and sometime wiring and plugs

USE SEARCH PLEASE

pmercury

iTrader: (2)

https://mbworld.org/forums/m275-v12-...-platform-142/

pmercury

iTrader: (2)

then repairing them here is a good options as they should never go wrong again (not tested by me but read everywhere)
http://www.v12icpack.com/