Massive Revving on Startup? Anyone else?
 

Got the car in December/Jan of 2018. I've had the "popping" sway bar as has been mentioned in other posts. Recently the car has started to have some...unique issues on startup.

With increasing regularity, the car will rev to about 4,500 RPM on startup without me touching the gas pedal (see attached videos). Has anyone else had this issue? The car already spent a few days at the dealer trying to re-create the issue with no luck. Car has not stored any codes or thrown a CEL. Has anyone else had this happen to their car?
The concerning part is the lack of error codes or any CEL, especially when the issue it throttle control. Car will be going back to the dealer in the next few days for the second round of testing.

Videos:

I've had it happen once. It seemed to happen when the revs dipped close to stalling on a cold start and the engine attempted to prevent a stall by revving the engine...it just MASSIVELY overcompensated, sending the revs halfway to redline instead of a couple hundred rpm as most other cars do. You're not alone.

Mine opens up strong but not like that ever.... do you live in an extremely cold area and park outside?

his outside temp gauge reading 73 fahrenheit on startup

Oh ha, i just watched the vid from my phone real fast...

Cold starts sound the best, so it's just giving you a little "aural" pleasure. =)

ha ha... nicely played... Pulp Fiction ref?

I live in SoCal, cold days here are 62 degrees. The strange thing is that it is not isolated to cold (relatively) starts. It also happens if i drive the car, park, and start it about 2 hours later. It has revved like that 5 times in the last week and of course behaves properly when at the dealer.

I had another strange electrical issue with the start/stop and i am starting to fear some more widespread software/electrical problems exist with my car. Glad to hear i am not alone.

North County San Diego here, car has never excessively revved on start up. Didn't do it in the cold either for the two weeks I had the car in Germany.

Hopefully it's something minor that a reflash will take care of.

This can't be normal.
My car has never done that, and I'm living on 78 degrees north, I received my car in the coldest time of year (march), I'm living on Svalbard.

It is 100% not normal. I have been keeping a log of when it happens, how many "normal" starts in between, and the time it was parked prior to a high rev start.
Car was at the dealer for a few days and were unable to recreate the issue. They did update some software but it clearly did not fix anything.

Once i can narrow down the circumstances that will recreate the issue i will bring it back to the dealer. Until then i wince at every cold start that revs that high - i can image that it will not good things to the motor over time.

Any resolution? I recently had it happen twice in the past month. Never happened before. Always on first start of the day.

Not at all. Now it happens even more frequently. I am up to about 1x per day, usually after the car is driven and then is restarted about 3 hours later.

When they were fixing the misfire issue they replaced the entire ignition and fuel system four separate times and nothing they did fixed my issue. I am in my last stages of the buyback process and i hope the car holds together until then. After all of these issues that still persist after the misfires, i feel like there are other core issues the MB cannot diagnose or fix. Best of luck but if i could give you any advice after all of this BS, take it into the dealer asap to start a record of the issues in case your car progresses to the point where i am now.

Best of luck....

Orange County here.

I have a late production E63S, and thus far I haven't had any problems with high revving. I mean, when it's cold, yeah, it'll rev around 1000-1200 for a few moments, then come down, which seems pretty standard to me. When warm, it just starts up as normal. If you're stock, I couldn't guess as to why it's happening. Did they fix a lot of these gremlins with the late productions cars? Luckily, I haven't been seeing any of these issues yet.

My production was one of the earlier ones, bought the car in Dec of '17. The revs will happen almost randomly but it will happen most often if the car is started 1-3 hours after being driven - thats as accurate of a condition set i could come up with.
The car is 100% stock. Because the car never threw a related code, i would imagine that there is some sort of engine parameter to keep it from stalling on startup and whatever it is is majorly bugged. The car also has the most up to date software version.

MB hasnt fought me on the buyback but i believe part of that has to do with California's extremely strong Lemon Laws. I am tempted to get a 2019 (if they are ever released from the ports....) but after this whole debacle i am going to hold off and let other people be the guinea pigs. If they dont know what is causing it, they havent fixed it. If they fixed it unknowingly, it means they still dont know what causes it. So much for the German Engineering trope...

Man, that's strange. :/ Sorry for the troubles. I feel lucky. So far, I've dodged all the bullets and my car has been running strong. No strange behaviors or anything, no codes, etc. I know California really screwed the pooch on the emissions crap. I love this car, and I'm really praying it doesn't fall into a buyback situation, myself.

Ive been dealing with this issue ever since ive had this car. Ive taken it to the dealership and they have reflashed and updated the software and still no luck. It happens every now and then randomly. Doesn't seem like weather or even cold start is a factor to this. A little relieved im not the only but this really concerns me. If it helps I have an Edition 1.

@loscar63 Even after they replaced my ignition system four times, updated all the software, and test drove it they claimed they were never able to recreate. It still happens and it seems like it happens more often. Now that the buyback is being finalized, idgaf about it. Its obnoxious and always seems to happen at the most inopportune times, but i wont have the car in a few weeks so i can live with it for now.

My only advice to you would be to take it into the dealer to document just in case it gets worse or you have other issues that pop up. Best of luck...

Anyone get any resolution to this issue? I'm finally taking mine in next week. It seems to happen when starting right about 1.5hrs after being driven.

I hear you. German expertise and quality had been always recognized here in Europe but the last 15 years or so quality has been on decline across products. I guess it's all about this crazy idea of companies have to give more and more profits each quarter and each year. Something has to give

@Cactus 757 Exactly the interval that would trigger it in my (lemoned) car. Good luck having the dealer recreate it. When i pushed the SA about it, she said they were able to recreate it a single time and since they didnt have the proper diagnostic equipment set up and the fact that it didnt throw a code meant they had no idea what the cause was. This issue was just basically ignored the entire time my car was in the shop. You also feel like a real ******* when it happens and you are in public or a valet....

I got my car back from the dealer last week. They were able to duplicate the problem. Turns out the #6cyl injector was leaking when hot. So far I haven't had it happen since having the car back.

Having same issue with 2020 sedan.
 

Hello all,

I have this exact same issue. At first I thought I had left my foot on the gas but it kept happening. Only after the engine was warm and I could reproduce it every time. I let the car get empty then changed out the gas and it went away. Have not been able to get it to do it since. I talked to the service people and they said they never heard of it, however they told me to drive the car in eco mode. He said they had 2 come in for leaking injectors and the symptom is a stalled engine in eco mode.

My question is, other than just waiting for something to happen . What can I do to figure out if I do have a leaking injector like the person who posted above?

Thanks

Hello guys

THIS IS NOT A ISSUE.
High Rev on Startup called in Germany
EMOTIONAL START