My s65 had 4-5 rough starts back around Xmas time.....it would sputter, cough then stall....then after a few off/on cycles with the ignition and a couple start attempts it would finally start and run fine- my Actron told me the code was a multiple cylinder misfire......ie, the whole drivers side cylinder bank was on the Actron. I bring it in to my dealer assuming it was a near-bad coil pack and I was told that there was no issue with the car, or the coil pack. My tech (as sharp as they come) told me that the refineries have changed their winter blend of gasoline and it's causing the ecu/car to misfire then throw the codes. He said he had seen 13 v12s in the past 3-4 weeks for the same issue, including 2 from the owner of the dealership......and they all had the same codes/symptoms. The best part?....there's nothing they can do until amg writes some updated software to deal with the issue, and that's not expected to be completed until summer time. It wasn't the end of the world as it only happened 3-4 times over 40-50 starts and it only happened at start up and then ran fine.

Now, my car hasn't thrown the code on start up in 4-5 weeks, instead it's throwing the C/E light and misfiring when the car gets under the slightest load/boost. I literally cant let the car downshift from any gear too fast, or too aggressively or it'll throw the light and go into limp mode......which requires me to pull over, turn off the ignition, and restart the car to get it to run/idle normally. So I bring it back in to the dealer last week and my tech was out, but another amg tech advised me that it's still the gas issue. Im now only buying 1/4 tanks of gas at a time praying to find one without this "blend". I've now ran 3, quarter tanks of gas though my car from 3 different stations/refiners and it's still having the same issue and throws a misfire on cylinders 10, 11 and 12.....or all 3 every single time I get the C/E light.....and I can produce it at will. The fact that i continually get the codes from The same 3 cylinders make me think thats its not a fuel issue this time? I would think if it were fuel, it would be an entire side of the motor, or both sides.....not the same 3 cylinders everytime It's agonizing to drive and is arguably not even safe.

Is anyone else experiencing this? I'm in Houston and can't possibly imagine tha every v12 Rollin around town has issues like me? Am I really supposed to continue driving this 200k dollar "flagship", big, bad azz, luxury sedan with misfires and check engine lights until refineries decide to change the refining receipe???? Or until AMG has time to find a solution???? Are you kidding me?..

 

Had a similar issue with my S600. I drove it around lightly for several hundred miles, but any load over 4k rpm threw a misfire. Hate to say, but in my situation, it turned out to be a bad coilpack. Runs like a charm now and I'm in Chicago w/the same BS winter fuel blend.

 

Sounds like the dealership is full of it. I would look at the coilpacks as well.
Check out line #27 in this post.

https://mbworld.org/forums/s-class-w...2003-s600.html

Good luck, Johan

 

The OP have given good advice.

Have you used Techron regularly? If not start using it! It makes gas issues that lead to misfires too go away. In my part of the world I use only Shell 93. Excellent gas.

Hope this helps.

 

Busa, I did not have the difficulties with start up but I did have problems awhile back about the car throwing codes under load. Just like yours it would run bad until you turned it off and restarted it, then it would run fine until you went into boost again. It ended up being a bad coil pack. The good news was that once the coil pack was replaced it ran much better and just sounded better and more clean at high RPM.

The car is noticiably quicker with the new coil pack.

Good luck

 

I had a similar problem, it is not the gas, mine turned out to be a bad ignition switch. Of course they only figured that out after changing all 24 spark plugs and bleeding the intercooler. I had to change dealers though the people at Benz of Coral Gables were idiots. Benz of Miami is much much better.

 

similar issues on my S65 with 33k miles and would give misfire/limp mode with check engine light. It would happen under load only as I could grandma drive it all day and it would be fine. Replaced the coil pack on the driver's side with spark plugs and it is now fine. I would doubt fuel would give it such an abrupt check engine unless the OBD saw a misfire. "Winter fuel" is a lame excuse IMHO. I could understand some cold weather chugging or slight stumbling but nothing like you have stated.

 

what makes more sense logically....You can produce a CEL at will due to a random winter fuel issue or a CEL due to a bad ignition coil that always points to the same cylinder? Your argument is solid and those techs need to listen to your specific scenario.

 

Sounds like a coil pack to me. I had similar issues... drive it like a grandma all day and all is well. Anything above 4K RPM would instantly throw a CEL and go into limp mode.

 

I had a similar start-up issue too... brought it to the dealer they said there is no codes and the car starts fine for them.

I bring it home and it's doing the same thing again. I changed the oil, cleared everything with SDS and now it starts like a champ...

Here's an audio clip of my car on warm start: http://www.v12biturbo.com/site/_upload/w220s65start.mp3

 

Update- once my tech was back from vacation he looked at it and immediately called me to tell me it was a coil pack, drivers side. He replaced it and I had my car back in 24hrs......runs perfect now. This is a perfect example of why I only trust MY tech......the only time my car has ever been misdiagnosed was when my tech was on vacation. Go figure.

 

Glad it is fixed! Winter fuel...not!

 

Wow you god *&^# tool, stop bumping up old @$$ threads in random sections with your rant. This is not how to get help.

 

GEEZ it Looks like BBBSS needs to get some more sleep...talk about rants...
Mike

 

Are you talking to me, tough guy?

 

What was ur fix for ur missfire mine does the same thing after 4 k any ideas

 

Several members stated above that the issue is with the coil packs. Now you just you have to figure out which side.

 

Po300 and 3 individual cylinders on each bank ignition control box between the engine was swamped out and tested is it possible both were bad or installed wrong new plugs new coil packs anything over 4k sometimes it bucks and hesitates with no cel sometimes it feels week like no turbos kicking it them sometimes the cel starts blinking for a few seconds then goes solid after that I turn off restart and run fine unless floored again then sometimes not so often if is completely fine wot and all