My C300 "farts" in Sport+ mode. Why?
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From: Seattle, WA
C300W4
My C300 "farts" in Sport+ mode. Why?
I don't usually drive in Sport+ mode (normally I use Sport Mode) but today I noticed that under hard acceleration when shifting gears, in the lower gears (like going from 2 to 3) there is a noticeable "fart" or "burp" noise (I think coming from the exhaust?). Kind of like the sound some motorcycles make sometimes.
This doesn't happen in Sport or Comfort mode.
Is this normal or expected? Bad or good thing and why might it be happening only in Sport+ mode?
This doesn't happen in Sport or Comfort mode.
Is this normal or expected? Bad or good thing and why might it be happening only in Sport+ mode?
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2016 C300
Ha! You're gonna make the C450 guys weep. So that sound is known as a "crackle" and it occurs when unburned fuel is allowed to enter the exhaust, where it spontaneously combusts. It's very prominent in the C450's AMG tuned exhaust in Sport + and most owners love it, but there's been reports of C450s suddenly ceasing to crackle. This is pissing the 450 guys off, since it's a part of the car's character.
Meanwhile I'm gonna try to get my C300 to do it tomorrow!
Meanwhile I'm gonna try to get my C300 to do it tomorrow!
Thread Starter
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From: Seattle, WA
C300W4
Hmm interesting. Still, why doesn't this happen in Sport mode under similar hard acceleration (approaching the red line, but don't need to necessarily reach the redline).
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
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2016 C300
Originally Posted by Jadis
Hmm interesting. Still, why doesn't this happen in Sport mode under similar hard acceleration (approaching the red line, but don't need to necessarily reach the redline).
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
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From: Eastern Massachusetts
2021 E450, 2020 C43, 2015 C300, 2007 C280
More than just a programmed noise?
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From: Long Island, NY
ML350 BTC & C300
I feel the car is fastest in sport mode. I'll use sport+ only if I want to make that pop noise. I noticed it does it when the car is under full boost and you shift around 4-5k rpm.
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2016 C300
Originally Posted by xMB007x
I feel the car is fastest in sport mode. I'll use sport+ only if I want to make that pop noise. I noticed it does it when the car is under full boost and you shift around 4-5k rpm.
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From: NYC
2014 C300
Hmm interesting. Still, why doesn't this happen in Sport mode under similar hard acceleration (approaching the red line, but don't need to necessarily reach the redline).
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
It ONLY happens in Sport+ mode.
I can do it at will from either a stop or starting at low speeds in the lower gears like when I speed up on the highway entry ramp.
As others have explained it has to do with gearing. Sport+ will help the car stay within the power band giving you quick access to torque/hp when driving spiritedly.
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Joined: May 2014
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From: NYC
2014 C300
Ha! You're gonna make the C450 guys weep. So that sound is known as a "crackle" and it occurs when unburned fuel is allowed to enter the exhaust, where it spontaneously combusts. It's very prominent in the C450's AMG tuned exhaust in Sport + and most owners love it, but there's been reports of C450s suddenly ceasing to crackle. This is pissing the 450 guys off, since it's a part of the car's character.
Meanwhile I'm gonna try to get my C300 to do it tomorrow!
Meanwhile I'm gonna try to get my C300 to do it tomorrow!
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2015 C300 RWD Sport Premium
I typically don't drive in any other mode other than Sport+ and I have never heard any snap, crackle, or pop in over a year of ownership. I would love for someone to post a sound clip.
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From: NYC
2014 C300
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'15 Black w205 C300, '02 E46 M3, '94 FD3S RX7
That noise is not un-burnt fuel in the exhaust. Its the blow off valve from the turbo venting into the airbox. If you vented it to atmosphere, it would make a "PSSSHHHHH" noise, that I assume Mercedes didnt want in a non-sports car, so they vented it back to the airbox to quiet the sound.
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From: Long Island, NY
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Yes I know that but I'm not a fan of the way it changes gears as it feels like it chokes when it shifts. I feel sport mode shifts faster & smother than sport+. To me the only benefit for sport+ mode is the pop sound.
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From: NYC
2014 C300
Sport+ is designed to shift harder. It's not supposed to shift smoothly at all.
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From: North San Diego, CA
2015 C300
That noise is not un-burnt fuel in the exhaust. Its the blow off valve from the turbo venting into the airbox. If you vented it to atmosphere, it would make a "PSSSHHHHH" noise, that I assume Mercedes didnt want in a non-sports car, so they vented it back to the airbox to quiet the sound.
this happens to most cars now that have a decent tune on them or an exhaust that's loud enough to hear it. it has nothing directly to do with a turbo...
watch at minute 1:44
<iframe width="560" height="315" src="https://www.youtube.com/embed/kDaNf8MW6qU" frameborder="0" allowfullscreen></iframe>
