I'm having the CES nightmare as many have described. Car has 20,000 miles and is out of warranty. Mine was declared a lemon and bought back. Presumably fixed by MB when I came along and outfit I bought it from said it was some minor software issue. I took it to a MB dealer for a full pre-sale inspection and it was declared to be perfectly fine. It was for a couple of years and then the nightmare began. CEL and limp mode. Light is on solid. If you shut down the engine it stops limping unless you accelerate hard and then you wish you owned a different car. So, off to the dealer. That was two months ago and it is still sitting there -- outside, not pristine in my garage. Sucks. They are doing all the tests, new plugs, new coils, injectors, smoke test this test and that test. Worst part is it's an open ticket like at the bar and the whole place is ordering the finest scotch with no end in sight. They are "talking to Germany" now after weeks and weeks of going through all the steps and coming up with no reason. Latest is Germany says to replace the engine control unit for $2200 and I have to agree to buy it regardless of whether it fixes the problem. How does that jingle go? The best or nothing? I got nothing but headaches and costs. I have a case open with MB NA for what good that does. I think they just send notes to the dealer that the customer is unhappy. I'm ready to get rid of it if they ever fix it because I suspect it will crop up again. They gave me a loaner -- some new econo sedan benz. It pretty much sits in the driveway and I use my other car but I am a very unhappy camper.

 

I'm sorry to read about your issues, and I don't think having your car at a dealer or independent shop on an open ticket is the best way to get your issues resolved in the end; they are all commercial profit centers. Try to find a capable local enthusiast with the time to diagnose your problem. If not, cut your losses and move on.

Been there and done that.

LOL,

HK

 

Prime example of why you never, ever buy a lemon law big body benz. I would go get it and take it to a smaller specialist shop that can properly diagnose and fix the systemic issue. These are not bad cars with some fatal flaw, they are just touchy to any issue. Any competent MB mechanic should be able to sniff out the problem without simply throwing parts at the problem. That is the biggest issue with most dealer shops, they tend to just throw parts at an issue because most of the stuff they work on is covered by a warranty and this is simpler than actually understanding how to properly diagnose the problem. Could be something as simple as a loose or corroded ground. Any shop telling you to buy a $2200 part that may or may not fix the issue is pretty telling.

 

ECU software update
new plugs and coils
check the vapor separators for plugging/failure

This is a 4.0 hot vee engine, correct?

 

sorry to read this. It is quite a terrible experience. You having the newer model and having this issue sucks. I get your frustration. I hope you can rebate any cost incurred from the dealer... when I bought my car I was so tempted to take it to the dealer and have them check. But i figured that is not the best route. They are quite cookie cutter, if they cant solve the problem, they definitely dont want to look stupid so they will try various things that "may" cause it. Chances are they havent found the issue and changing the ecu may or may not make a difference. I am still anxious with the guy i go to, local and only works on amg but still... it is tough to find proper service when things do go bad. There are some good german specialist shops but labor pricing can be expensive...the thing with warranty is that you have that as a backbone in case something goes wrong. Best of luck, this sucked to read but i hope you get this resolved somehow with mercedes...

 

Thanks for your responses everyone. I'm hoping someone comes along with THE answer on the board, but I've made the decision to stick with the folks that made the car to fix it. I'm fortunate to have other rides, including a new 392 Hemi Jeep to keep me occupied for now. I do need my long range bullet train back soon though. No resolution yet, waiting for Germany to advise the dealer about why they are unable to get the ECU programmed. Hopefully they figure it out and that's the end of the story. Both the dealer and Mercedes NA have indicated a willingness to help with whatever the bill ultimately is so we will see, and I'll keep you all posted. I must say that I am surprised at how many folks with this engine in their cars have had similar issues. I've yet to read what the hell the "common thread" is that causes it. From plugs, to coils, smoke tests, gas, injectors, electrical and back, still a mystery with mine. The fact that it was bought back as a lemon when it had less than 14K on the clock by the original owner is remarkable. I was comforted ( obviously wrongly ) by the fact that Mercedes had fixed whatever was the problem then. I added 6 thousand miles before this situation cropped up. I also have a 2009 SL 550 that is a honey with no troubles of any kind but then it isn't as complicated as this fellow. That said, watching that top go up and down is a bit of magic. Oh yeah, that battery in the trunk is a PIA to keep charged, but I can work with that. Fingers crossed they sort it out soon. I just put new wheels and tires on the big boy for the winter and its getting cold here now.

 

Quick update on my 2018 S63 with 20K miles. New ECU installed and programmed ( Germany sent over a software update for the new ECU which wouldn't program ). Problem persists -- CEL and misfire codes. Wonder what they will try next. The ECU was $2200 for the part and I was told I had to pay for it if it works or not. Waiting for Germany to come up with another idea now -- at my cost. I'm all in now, what else can it be? I simply don't believe it can't be fixed, and I have never experienced anything like this with a car and I've owned many. The best or nothing?

 

More likely causes (known problems on the M17x engine in your car):
Coil packs
Spark plugs
Plugged vapor separators

Less likely causes (common problems on the prior M157 engine):
oil in the wiring harness at the cam sensors and cam magnets
bore scoring/low compression

Mercedes is not the best, there is no question about this. The recently released Consumer Reports reliability survey listed MB in 29th place out of 30 brands.

The mid-200teens until now have been a tough period for MB owners as it relates to new car delivered quality and short-mid term reliability. MB's products are simply not reliable, or high quality as defined by absence of defects compared with other brands.

 

Thank you for the reply! Compression is good, all plugs and coils have been replaced. Smoke test was fine. Gasoline is fresh and correct ( they drained and replaced in case ). Wires and grounding all checked out. Just replaced the ECU. Injectors replaced. We'll see what Germany dreams up next. I'll keep you posted. I had a BMW 740i from new in 1998 and had no troubles for 120K miles. Two Audi A8's that were trouble free too. This experience is making me want to go back to them. I thought the Benz was going to be the pinnacle. Turns out to be a PIA.

 

Wonder if it could be a timing issue. The specific codes they are getting in Xentry should be able to point them at least in the right direction. Something sounds fishy here.

 

Agree. The information presented on this thread does not add up.

@quadcam please list the codes that the ECU is generating. Thanks.

 

You might want to have BenzNinja have a look.

 

Oh it adds up alright. The Dealer advised yesterday that in fact no injectors have yet been replaced but Germany advises that two of them appear suspect. After the new ECU made no difference ( but I have to pay for it ), I gave the go ahead for replacing these two. Something like 3 grand more. I think we are around 9 grand now in time and materials, and we are on day 61 with car at dealership. Rough having to pay insurance all this time too. Sigh. Should know by tomorrow if this latest idea does the trick. Of course, if it does, the first thought is -- how come you guys didn't go after that first? I think the answer is that they had no way to pinpoint that and besides it is expensive as hell to get at the fuel rails etc. I'll ask what the codes they are seeing currently are.

 

Injectors look to be around 200 bucks each for Bosch units. How is this 3K more. If they are ripping the whole motor apart might be worth 800 bucks or so in parts to replace them all. Injectors should not fail at 20K miles though.

 

I get your point, on the other hand "preventive maintenance" at this stage seems absurd you know. I mean, we're in this is what Germany says to do land. The highest tier guys. It's kind of out of my control in that sense as they are still attempting to figure out what the hell the problem is. We should know tomorrow if replacing two of them fixed it! If not, I wonder what the next guess will be. What a saga. Once they do finally fix it, imagine the box of parts I should be bringing home.

 

Codes are p030022 and p0302200

Explanation is combustion misfiring -- signal amplitude is greater than maximum amplitude. Misfiring on cyl 2 detected. Then it randomly sets faults for various other cylinders misfiring. Germany told them to replace 2 injectors, one on each side.

 

Not a fan of direct injection for this very reason.

 

And on the 65th day -- No resolution 2018 S63 Check Engine Light Persists
They just put in two new injectors per Germany ( one on each side ) and the problem persists. Germany said the next thing to do is replace the fuel rails. Another $3500 or so to spend. The nightmare before Christmas continues. We are approaching 13 grand at the dealer with no end in sight. Mercedes North America has offered to pay 10% up to $1000 of repairs. The dealer has offered to match that. I've asked the GM about trading it in on a new one. To recap, I bought it as a branded "lemon" that had been repaired at 14,000 miles by Mercedes. Presumably it was some minor software issue they had to update. It then went the auction route and it was exactly the car I was looking for. MSRP was over 170K new with the executive package and a slew of other options. I paid just under 100K for it. Before I bought it with over 1 year warranty left on it, I took it to a Mercedes dealer for a full pre-sale inspection and there were no issues. I've owned it for 3 1/2 years and 6K miles with no issues until the dreaded Check Engine Light came on with misfires and limping under heavy throttle. Took it to the dealer on 10/6/23 figuring it would be something they would sort out in a matter of days. Germany has them run a slew of tests before the engineers that created the car get involved at my cost of course. Did all that and now they are replacing parts -- from plugs, to coils to injectors. Fresh gas was tried. Next they will replace the fuel injection rails. The lesson I'm learning is not to own one of these unless it is under warranty. Not sure I want it back anymore. Maybe I'll try the E version but if the engine is the same I wonder if I'm asking for another nightmare. Being under warranty would be a security blanket on a new one for sure, but being without your car while paying insurance on it for months while it sits outside on the dealer lot with mechanics hopping in and out test driving is a horror story. I'll keep posting till the saga is over.

 

This is getting ridiculous. You are paying them to diagnose the problem and it sounds like they are simply throwing parts at the car with no understanding of how to properly diagnose the root cause. I wonder if you got some bad gas and it has gummed up the fuel rails and injectors. My guess is they keep on replacing perfectly good parts until someone who knows what they are doing actually figures out the root cause. So what is your walk away number, 20K, 30K?

 

Agree, it is ugly. I'm guessing 15K by the time they figure it out. That said, who knows the car better than the folks who build them in Germany?

 

Sorry to hear of the challenges.

The evidence is mounting that another MB engine, the M177 4.0TTV8, is not worth owning out of warranty. It has misfire problems when launched on several vehicles, related to coils and software. Lately, oil vapor separators are failing (plugging) causing crankcase overpressure which fails the rear main crankshaft seal. And the saga in this thread, related to injectors and fuel delivery system. Three strikes and this engine is out.

M157/M278 4.7/5.5L TTV8 cold vee: bore scoring, oil in harness, and a handful of other moderate to major issues
M177 4.0 TTV8 hot vee: coils/software, injectors, fuel delivery and oil vapor separators

Don't touch these engines.

 

OP.... The V12 still uses port injection and in 279 flavor doesn’t suffer the ignition coil pack drama of the 275. Proven engine that makes plenty of YANK when the loud pedal is applied.

Direct injection isn’t just a disaster for Mercedes....

 

Do you have specific examples of the instances of the problems occuring on the M177 4.0TT?
I'd love to see links to the cars/people who've had the problems you're referencing. Even if they are online articles or magazines or anything else. Appreciate the info

 

Days and Dollars flying by with 2018 S63 still at dealer for months. Last update was they were told by Germany to replace the fuel rails. My cost over 3 grand. That didn't fix it. The car only has 20,000 miles. Cost for this nightmare is approaching 13 grand and the latest advice from Germany is to replace two fuel pumps. Another 3 grand or so to see if this fixes it. Should know by Friday. Can't throw the car away, can't sell it. Car is a delight when it runs as designed, but this experience will have me looking elsewhere for next car. The best or nothing? NOT.

 

This is silly, any mechanic worth anything can check fuel pumps for pressure and flow off the fuel rails with Xentry. As I have said before, they are just throwing parts at the problem with no real diagnosis.