eatmydust

Hello

Been driving my new C43 for about a week now. The first few days the cars responsiveness was amazing. Suddenly today, i noticed from a compelete stop there is a huge delay, and i have to deperess the pedal almost halfway to get this thing moving. Once that initial lag of about 5 seconds is over it seems to kick in? It wasn't like this just days ago. Anyone else experienced this? Just pressing the pedal that far just seems wrong. Also near the bottom of the driver screen there are two guages, 1 says charging and 1 says power. I noticed the power guage is showing empty now and it was showing full bars before. I'll take a look at the manual tonight to see what that is suppose to indicate.

Dima

MBUX then AMG Performance then Engine. It shows current power usage, so you need to try to see if it reaches maximum with hard acceleration.

eatmydust

Haven't reached the 1000 miles break in yet. But might try anyway.

Noticed it got worse in heat. But in cool weather it seemed to be okay? So odd.

Dima

Perhaps you should call a service advisor? I know there is no code visible, but if what you're feeling is true, it could be the turbo as it is sensitive to temperature, but could also be normal transmission adjustment.

superswiss

Sounds like your car might be in limp mode. One way to tell is if you go the AMG performance screens as mentioned above and then Engine take a look at the scale on the hp graph. If the max hp shown on the graph is less than what it should be, then you are in limp mode. You don't get a CEL or anything if the car is in limp mode, but you'll have to take it to the dealer to diagnose why it went into limp mode, fix the issues and take it out of limp mode. There've been some reports of the electric turbo failing. It's a brand new component and it's used for the first time in the C43. There are also no replacements available at the moment, so if your turbo has failed, then you likely gonna have to wait a while for a replacement part.

eatmydust

So i decided to put the pedal down today to see whats going on. The graph got to 392hp without issue. The responsiveness after rolling is fine. Its just the initial moment you accelerate from stop that is weird. Maybe it's just transmission behavior. Idk. For now it seems the power is sort of there

superswiss

There's still the possibility that the electric turbo isn't working properly. It's supposed to spin up the turbo using the electric motor from a stop until there's enough of an exhaust stream to keep the turbo spooling. This is supposed to virtually eliminate turbo lag. W/o it, the small 4 cyl engine lacks oomph off the line. I haven't driven the C43, but I've driven this engine in the A45S w/o electric turbo and it has turbo lag the size of Texas. Also, in case of the C43 the electric turbo uses the 48V system. If your 48V battery is low then that could be another cause for the turbo not spooling up as it should. The new C63 uses a 400 Volt electric turbo, so it has much more power, but based on folks who have reviewed it there still appears to be quite a bit of lag.

eatmydust

Interesting this makes a lot of sense. I'm going to wait until I hit 1000 miles before I make a conclusion to see the dealer. I have no cel or anything and since this is a new turbo, probably nothing has been established yet out of Germany about any widespread issue. I really hope there is something to get fixed.

A few times the lag was very bad. Hit the accelerator almost halfway down and nothing then after about 4 seconds boom the car lunged forward and power appeared.

eatmydust

We've had 2 others post on this sub and other sub with turbo issues but they never followed up. Would be nice to hear what was done in their cases. But they both never posted again

alexasa

iTrader: (1)

It's weird coming from the W205 but I think what you're experiencing is totally normal

eatmydust

Hmm. Just doesn't make sense to me knowing it should have rather good jump with this new turbo

Dima

I don't think I have a delay from the stop. Most of my driving is from one traffic light to the next so I would've noticed I think.

eatmydust

Also noticed today when parked idle the engine does a shudder every few seconds only after sitting for a while. sigh idk. Maybe I'm overly alert but the shudder is noticeable by passenger as well. It shudders us at our seats. Man I hope this will all work itself out

AzurSL

That doesn’t sound normal at all. Something sounds clogged up big time. I’d bring it in.

Dima

Fewer cars in the city during this time of year, so I tried accelerating hard at every traffic light from the stop - I had no delays at all even in comfort mode, it was instantaneous.

alexasa

iTrader: (1)

shudder? the engine should have some decent shake when in sport mode - something you can feel in the cabin and probably one of the reasons why dynamic engine mounts are being offered - but again it should be steady/consistent.

I do think it's lazy off the line - I'm not sure how the electric turbo works but it might not work at all at idle? Not sure - would have to do more research.

eatmydust

Shudder only happens after starting car after sitting over night and shudders while waiting at idle. It starts in comfort mode. Once I start driving it goes away. and for rest of day usually it stops.

Yeah off the line the turbo lags at first, later kicks in.

eatmydust

How about half pedal? My lag is evident with moderate acceleration

Dima

nope not there. the thing about electric turbo it's always there ready as opposed to conventional turbo that needs to wait for fuel to get there. So there should not be any delays.
I wonder if your dealer would let you try another one to compare.

humblehyper

I have the same exact issue on mine, just got the car from dealer on a knock sensor issue, they said it was loose from factory, it has power now but at a stop it looks like the power gets cut off, it even jerks sometimes.

eatmydust

Did you get a cel?

humblehyper

Yes before they fixed the knock sensor issue.