Maybe you guys know what is going on with my car. 2010 c63.....


About a month ago I took my car to dealer because every meow and then it would sputter and shake, while in drive or park, but would smooth out once I started to accelerate. no CEL came on. After a little driving it quit and all was good. Dealer couldn't get the car to replicate problem but found out I needed a coil pack replaced. Done.


The car continued to do the sputter thing, but I figured out it was every time I filled up with gas. And yes I use 93 octane and only from reputable gas stations. And I never "top off" the tank. When the nozzle auto shuts off, that's all the gas I put in. So I take it back to the dealer a few days later with only a half tank of gas. The head tech goes with me to the gas station for a fill up, the car to repeats the "sputter". Tech says its my charcoal canister getting flooded. 4 days later I get my car back with the needed repairs.


Meow, up to date, car ran fine for a few days and then it sputtered again but this time so bad that it wouldn't even move if I pressed the gas. CEL came on. I shut it down waited 5 minutes. Then started up again. Sputtered a little (no CEL this time) then smoothed out once I started to accelerate.


Car is on they way back to the dealer meow. Lets see what they come with this time. I have only owned the car for about 2.5 months but is been the shop a lot lately. kinda sux.

Check all spark plugs, fuel filter, clean air filters......also check to see if you swallowed a cat...

all of those have been checked and are new.


As for the 'MEOW" I was just throwing in a bit of "Super Troopers". Wasn't sure if anyone would catch it........I guess not.

Don't worry, I cat it.

Loooool!!!

First thing that came to my mind when reading the OP was Super Troopers. Love that movie!

Was having the same issue. I replaced all spark plugs and coils. Same thing. Shaking and and going into limp mode. Finally I purchased some Chevron Fuel Tank Cleaner and used two bottles back to back the way they told me to. Seems to be good now for two weeks. Got a CEL but its for a short curcuit for front left o2 sensor. No stalling or shaking. Maybe that will help. Also I dumped mobil and stixk with BP

Does it act the same if you don't fill up and stop at say 3/4 ?
If your charcoal filter is getting flooded it sounds like a problem in the vapor recovery system.

Actually I tried this and it still did it. I even thought maybe there was a vacuum leak so I replaced the gas cap as fast as possible after pulling the gas nozzle out. Which is a far fetched idea to try since the cap is off and I'm pumping in gas and air. but I still tried it. That trick worked ONCE.

If the dealer comes back scratching their head, I will definitely try this.


Thanks!!

I had a very similar issue before. Car would stutter and cel will go on. Rough acceleration and loss of power. Happened 3 times, I cleaned the maf sensor and it hasn't happened since the cleaning.

you need new fuel pumps, went through this exact same thing 3 months ago. idk why everyones saying MAF sensor or w/e..none of that would make the car sputter or choke..its your fuel pumps

It wouldn't hurt to just clean your MAF's before you dump the money and time on new fuel pumps.

Duly noted!! Thanks. This is all great feed back for firepower if they can't find the issue.

Normally I would agree with you 110%, but since my car has a warranty, I don't pay for any of this.

Take it to the dealership and tell them an internet super tech told you to replace the purge valve. When it fixes the car, ask them if you should take your car to dfw to get serviced lol.
the purge valve sticks open, you go to fill the car up, the gas in the fuel tank now displaces all the air/vapor and it pushes the fuel vapor from the tank into the intake manifold through the purge valve.
now you go to start and the air fuel ratio is all sorts of jacked and it misfires until all the fuel vapor is cleared out of the intake manifold.



fuel pumps? what does filling up with fuel have to do with the fuel pumps. They clearly worked just fine getting the car to the gas station and the other 99% of the time when it isnt being filled up.
I've never seen a maf sensor problem on a 156, why does everyone think these fail all the time lol.

Thanks so much for the advise. This by far sounds like the best advise. As for telling the dealer, I emailed my service drive guy the link to this page. He is checking it a few times a day. He has all ready advised me that he has sent this link to his shop foreman.

I had my purge valve stuck open for months and never did the car stutter...my fuel pumps slowly started to go and the car only would stutter if I started to get into it, they worked fine if I drove like a grandma

CEL will come off and on with the fuel pumps or sometimes blink if you WOT it to 7k RPM, CEL won't come on for a purge valve

Well the dealer called me last night and they advised that the purge valve will be replaced. Now that doesn't say whether it is the cause or not. but I guess we will find out. Service Drive Manager said that if this doesn't fix it, then the fuel pump is next.

Quick update***
Picked up the car Saturday morning. Had a small chat with the head tech supervisor. He told me that he actually read this forum link that I sent him. He agreed that the purge valve sound like the most logical fix and so that's what he did. We filled it up and no more shuttering or sputtering. I almost down to half a tank so lets see what one more fill up will do.


So far, it seems that it was the purge valve causing the problem. Thanks to you all for the help and advise!!!!

interesting to see MB check their forum, and to actually take it into consideration.

Well, my car is back at the dealer for the same issue. I was able to fill up about 3 times before the sputters started again.
I filled up half way just to see if it would still do it, and it ran fine. Stopped about 10 miles down the road to finish filling up and sputter started before I even left the gas station.


So far what has been replaced is fuel filter, charcoal canister, & purge valve.


Lets see what they replace next.

Told you it's the fuel pumps, I went through your EXACT situation 5-6 months ago, Replaced a bunch of parts and it was the fuel pumps in the end


It'll get worse, eventually you won't even be able to push the car past 3-4k RPM without it shaking violently

Fuel pumps are like $500 each..get them done..it's not that expensive

Thanks for advice. As for the cost I couldn't care less. It's all under warranty. Mercedes can pay for it. LOL

Car still at Mercedes, just got a call that the FUEL TANK failed the testing. Therefore I am getting a new Tank. Lets see if that works.
LOL
Round and round we go!!!!!