Carac

I got my 2010 C63 four weeks ago and had 1800 miles on it at the time of CEL (got break in over with asap). I was driving home from a relatives house last Sunday when the check engine light came on and when coming to a stop and idling, the car began to violently shake. Would almost stall when accelerating from a stop, then smooth out to become drivable above 20 or so mph, but definitely still way down on power. I was only 3 miles from home so I limped it home. As I pulled in my driveway the check engine light began to flash. Called roadside assistance and had the car flat bedded to the nearest dealer 45 minutes away. I came here and saw 4-5 other people had faulty cam position sensors that caused similar symptoms. Dealer pulls codes and believes it's a bad fuel pump. Says 2 banks threw faults. Is it possible a faulty cam sensor could either give a false impression of a failing fuel pump, or cause damage to a fuel pump after driving for 3 miles? It's taken them a week to get a new fuel pump from Germany (which is supposed to come monday) and I don't want to find out later that a cam sensor was the cause of it all...and have to get another tow to the dealer from somewhere that isn't as convenient as my driveway.

P.S. I didn't buy from the dealer fixing it, and the dealer it's at is notorious for being unable to correctly diagnose a problem. Took 3 visits to fix a stereo and A/C problem on my sister's SLK.

503C43 ////AMG

I am wondering why you would send it to said dealer if they are notorious for incorrect diagnosis's?? Sounds like a 1 way ticket to headacheville

shardul

iTrader: (1)

hmm coil pack faulty causing engine misfire?

Roswell

Mine was a bad 02 sensor causing misfiring. Quick fix on the same day... but it sucks when it happens on such a new car though.

hhughes1

I experienced a misfire issue a month ago as well. Car nearly stalled as it was turning into a parking lot, started shaking and the cel started flashing. Also a strong smell of unburned fuel was present. Car was towed to the dealer and first thoughts were ignition related. Turns out to be a cam synch issue and a new cam sensor was installed. Problem still exists and they are concerned about software management. Specifically "the 1200 position of the exhaust cam was implausible relative to the position of the crankshaft". At that point they performed a "teach in of all positions" for the cam shafts and the car has been running great ever since.

Carac

Well, I've compiled a sheet of 15+ posts from this website of people with the exact symptoms I had, and hopefully they will listen. You'd think they would take the hour or less it takes to replace a cam sensor ~$40, rather than wait over a week for a $400+ fuel pump, only to have it not fix a thing.

503C43 ////AMG

I'm betting they make more $$$ of replacing the fuel pump so of course they would want to start there

JonMBZ

That's not always the case. MB requires printouts and faults before replacing certain parts, they also require that the parts be sent back for inspection/QC purposes. If they find out that the part was in fact not faulty, the dealer will get charged back for everything and have to pay for the parts themselves. MB is not stupid if the dealer was doing this (which wouldn't be something new) they would be in hot water.

503C43 ////AMG

looks like I might of offended an MB tech?? Thanks for the info though, very informative and instills a little more confidence in the dealerships . Carac please keep us informed of what the issue turned out to be...

Sathinas

Let's see:

Trust a guy who has access to all the MB related diagnosis equipment and experience, or take the the word of the owner as to what was wrong...

Sorry man, I'm going to go with the tech's suggestion. As mentioned above, a tech has to be very sure a part is bad before he/she replaces it. If that part wasn't bad, he doesn't get paid for the job. Gone are the days where a tech will throw parts at a car just to make more money.

If you're not satisfied with your dealer's tech department, go somewhere else. Seattle is only what, 3 hours away?

Carac

Paraphrasing the tech before I did my research: "it might be a fuel pump, since the cylinders aren't igniting (misfiring), we'll replace that first and see what happens." Not a very confident diagnosis if you ask me, and very flippant about it on the phone. Tone was very "I don't know what's going on, we'll just swap some parts and see if it works." I'm more ticked at the fact that they didn't try the most obvious and widespread issue with the C63 engine first. An issue that takes a few hours to remedy...instead of ordering a part from Germany that "may or may not" be the cause of the problem and putting me out of my car for a week when I've only owned it 4. Assuming this common problem is the source of my misfiring engine, I could have been back on the road after a day, instead of a week and a half.

Oh, and the next closest Mercedes dealer is over two hours away.

Sathinas

Oh, so this was over the phone? In that case, I retract my last post. I thought you took it in and they hooked it up to SDS.

ZephyrAMG

Hope you get it fixed soon and that you are back driving. don't worry too much. They will fix her. Keep us posted if you need any words of support here and there...

sparrow650

Had the same experience during the first 5k miles. The car was barely drivable past 45 mph on the freeway and felt like it was shaking itself apart. Scariest thing I've seen one of my own cars do. I pulled over, shut it off, restarted, and the issue (and CEL) disappeared.

When I took it to the dealership, they diagnosed it as a faulty cam sensor, and fixed it under warranty. The car runs fine, although sometimes I can't help but feel it's a tad rougher and less powerful since the repair. Still, I expected better quality from a handbuilt AMG engine.

JonMBZ

No I am not a MB tech, but I did work in the department that handled the returns of faulty parts, so I know how the procedures the techs have to follow to file a warranty claim and not be backflagged/debited for an unnecessary repair. The S/A probably just didn't have the full answer at the time and just throwing his thoughts out there. If the star is giving no codes or just generic codes it's possible they will start with the most common item. They will likely get their shop foreman/MB involved to get ok to start there. If MB thinks otherwise they will have them replace what they think is necessary to fix the issue. Either way it will get fixed at no expense to you, and worst case scenario you have a new fuel pump and new cam sensor. Win Win

Edit:

A further in-dept look into this would be what happens if they do find out the pump is not bad. Well first thing would be that if they still try to claim it under warranty they could get the claim denied then the labor/parts are all charged back to the dealer. The tech is back flagged the service advisor is back flagged and the manager/director is forced to write off the whole claim. Fuel pumps are cheap in comparison to a cam sensor so if it's a possibility they would want to start there. If they do change the pump and it's still not the part, the parts department will likely not accept the part back due to it being full of fuel and used (if they are wrong and decide not to claim it). Warranty is down 50% across the board now because the quality of the vehicles is so much higher now and service cannot afford to make mistakes like this and techs definitely don't want to make these types of mistakes either since their jobs could be on the line if they have constant diagnosis errors. I am not saying there are no stupid techs, but there are lots of policies instilled at the dealers to protect the dealer/MB and the customer from things like this. One of the biggest things the dealers are graded on is FFV (fixed first Visit) and CSI (Customer Satisfaction Index) those surveys you get in your email.

HBC350

What does "handbuilt" have to do with anything? The motor builder didn't manufacture that cam sensor from scratch. He bolted it on, just like most of the parts.

HBC350

There's such a thing as diagnosis. Not guesswork, but actual analysis. You don't want someone rooting around in your engine trying to replace a cam sensor that isn't even faulty, simply because it failed in someone else's car. If the sensor it bad, it will likely throw a code. Same with the fuel pump. And, if the misfire is as bad as you say, they can simply monitor fuel pressure and see if it is within spec. It is or it isn't. I don't think many reputable dealers are just throwing parts at cars in a hit or miss fashion.

sparrow650

MB goes to great lengths in their marketing to emphasize the handbuilt nature of AMG engines. Quality, craftsmanship, pride--these are hallmarks of this manufacturing process, and is one reason why owners believe such cars are worth the extra expense. One could buy "more car" or "more speed" for less money, but it's not unreasonable to assume that a buyer chooses the C63 for higher quality.

It's true that the engine builder didn't create the cam sensor and various parts that go into each motor, no more than a watchmaker or electronics manufacturer necessarily creates the parts that go into a fine watch or high end TV. But if a buyer pays more for a product advertised as one of high quality, in this case even going to the trouble of attaching a signed plaque to each one, then surely the owner is entitled to expect more.

ZephyrAMG

Indeed....+1

Roswell

^^ ditto x2 ... very well said sparrow!

HBC350

I agree that we are entitled to expect more than a failure at such low mileage. I was merely pointing out that the "hand-built" nature of the engine has no bearing on the likely problem you're experiencing. You tied hand-built to a failure to which there was no nexus. Would we all want MB to run each engine for 2,000 miles before putting them in the car and sending them to dealers, in the interests of trying to root out the rare failures that are a certainty? Probably not. Instead, we take them as basically brand new and a few of us get dealt the deuce.

I had a purge valve fail and set the check engine light on the way home from the dealer on the day of delivery. Granted, it was at 9K miles since I bought used, but distressing nonetheless. It happens. In a month your troubles will be nothing but a distant bad memory and you'll be tooling along in the car you thought you were buying once again.

Sathinas

Perhaps you're right, but you have to remember one simple thing...

That sensor was designed by a human. And as much as we humans would like to think otherwise, we're not perfect. As such, we can't make a perfect thing. Be it a sensor or something else.

Stuff breaks. It's life. Until human beings are the epitome of living things, we will still design and create stuff that will eventually break.

Carac

So, an Update. Got the car back after 10 days in the service dept. I've owned the car for 32 days...

Waited the 7 days for the fuel pump to arrive from germany, swapped it out...no change. They reluctantly order cam shaft sensors, replace them, and resync the cams as I suggested. Voila, car is back to perfect working order only a day after ordering the sensors. I happy to have it back, but still pissed it took so long.

hhughes1

Great to see you back and running. Forums like this one can bring to light common issues that are obvious from a global perspective but unnoticable at the single dealership level. This issue could affect dozens of cars but because the local service manager has not seen it before the diagnosis is delayed.

Roswell

Glad to hear you got your car back... that's all that matters. Go out & enjoy it now.