Migx27

Hi, new owner of c450. I have noticed that sometimes when I start my car there's an exhaust roar but occasionally is very mild. is there anything to do to have that all the time I start my car? I notice the car starts on COMFORT all the time even if i drive S+ all the time, anyway to change this. I read around that it cannot be change but just making sure
thanks

angeloxnet

it's called "cold start", a quick google search will explain more.

DapperStyle

1. The car will always start in Comfort with ECO on, no way to change it. In regards to the roar you hear - in the C450 Discussion Thread on the forum this was mentioned, basically if you turn the car off in Sport+ the next time you start it, it will "roar" a bit louder even though you are starting in Comfort. I recommend searching the thread for any other small tidbits about your car that might be of interest.

I believe the OP is describing the above and not a cold start.

Zorq

I believe modern cars have a cold start feature, not only benz, that when the oil temp is below are certain threshold, the engine will maintain a higher rev at startup until:
A. You put the car in drive
B. The "cold start" feature timer has exhausted


At that point, the idling rpm will return to normal. This normal idling rpm is same if you say stopped your car for an hour and return where the oil temp is still above the "cold start" threshold.


As the C450 is a AMG SPORT, shutting off the car at sport+ and re-ignition within a certain time frame will make the car Roar, but still return to comfort + stop-start tech. I can confirm that as I sat at the dealership re-igniting that demo car a dozen of times to verify that feature. The time frame as some of the websites states is 4 hours, but I didn't sit there for 4 hours to try. Hopefully that helps.

karan538

If you really always want to hear that roar then you can always turn once (or click once) when the electronics are on, switch to sport+ & then switch on engine.

nacklenakie92

hello,
im new for this site

nacklenakie92

hi,
welcome to this forum site.
Here you can find lots of things,
i suggest you for your question ,
you have to contact any other expert
right now i have no knowledge about
your query sorry for that
...............
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nacklenakie92

hi,
welcome to this forum site.
Here you can find lots of things,
i suggest you for your question ,
you have to contact any other expert
right now i have no knowledge about
your query sorry for that
...............
topten classified website

Don808

I've had C450 for a month. I've noticed two things about start-up: (1) On cold start-up, the engine idle starts high (around 1500 rpm) then slower lowers. Exhaust is very throaty then quiets as idle lowers. I live in Hawaii so this really only happens in the morning or after not driving for hours. (2) If I last drove in Sport plus mode and restarted the car shortly after, I get the start-up roar, as if I were stepping on the gas. Upon start-up, the display reads Sport plus then instantly goes to Comfort. The restart must happen very shortly after. I've read that it is 4 hours but it's not that long. I don't know the exact length, probably less than hour.

nvestr

I don't have a C450 yet, but the one I tried at the dealer would remember it's last known setting after startup for a few hours. The roar would be very pronounced when in S+.

If you want it to roar and the time since you last turned off has elapsed, you have to hit the Start/Stop button without your foot on the brake, blip the Dynamic Select switch forwards twice to get into S+ and then apply brake and re-hit the Start/Stop button.

Edit: sorry I guess someone already said that. Will read next time.

Don808

FYI, I must hit the start/stop button twice (ignition position 2) in order to change the mode. It will not change in position 1.