munis

My car would be hitting 5000km in a day or two and it has been 2 months since I got it. I made a video of me driving in sports+ a month after I got it and I made another one day before yesterday. You can definitely see the difference between them. The exhaust isn't as raspy anymore. The bangs on upshifts are getting quieter as well.

On a side note, if I do pump 94 octane, it does get much louder and kind of gets its voice back. But even then I feel it isn't as loud as before.

When I first got the car, it made a bunch of kids cry rivers because they though someone was shooting people around. Girls would scream in fear and boyfriends started to pull their girlfriends to the side of the road as if the car is going to explode.


All that still happens, but way fewer in number. And I am missing it. What gives?

Lionel_Hutz

It isn't unusual for an exhaust to change in volume and tone as it breaks in. But the octane thing is 100% in your head.

ShazV6

Yea, i cant do a quiet car especially in my C43. Its why i just went with a resonator delete and muffler delete . OHHH are those snap and crackles and pop soooo much louder and scarier. The drone can be bad at times honestly(when cold and in "C" mode), but when i get into it and can control the gears (When in S+ & M mode when the trans and engine is warm) it just puts a huge grin on my face.

munis

Any explanation behind why this happens? Does the exhaust pipes gunk up or something? Is it like getting dirty being an issue? I would be really interested on what exactly causes it to become quieter.

To be honest I really do feel the difference between 91 and 94 octane. May be you are right and it is in my head, but I honestly felt it.

Dthquazi

Exhaust pipes will coat with soot over time. This will take away some harshness from the tone. It will not be a drastic difference.

The only thing I can thing of for the difference in octane is that the car may be performing better with the higher octane. You may be pulling timing with the lower octane. It is unlikely that the Ecu would be able to detect the differences unless you are getting bad 91 octane. It is a possibility though. Are you getting 91 and 94 from the same place? Is the gas station that you get 91 reputable and busy?

When i ran my eclipse I had problems with some 92 octane. I would get detonation at medium boost. I got it from a decent gas station near my house. I started shopping around for gas and found that gas from another station performed better. I could tell a noticeable difference since timing wasn't being pulled due to knock.

munis

Anything I can do to prevent it? Thanks for the feedback!

Dthquazi

You really can't. It is just a byproduct of combustion engines. It doesn't mean that your car is running dirty or not well. Just happens. Also I added to my post above.

Lionel_Hutz

Particularly with aftermarket exhausts there is sometimes packing material in mufflers that breaks in. Even with OE exhausts simply heat cycling everything, burning off packing grease, and adding some carbon can change things.

Are you throwing the car in Sport+ when you use high octane gas, but not low octane?

5ilver-5urfer

I'm at about 10k km after 3.5 months (yes, I drive it way too much )
and I've noticed the upshift bang sounds less "tinny" and less violent lol. That being said, a lot of people were saying that this happened after the dealership updated the code on the car, but I'm guessing neither of us has had the car in to the dealership for service since purchase.

I'm thinking it's a combination of a couple of different things, these are purely my opinion and could be completely wrong btw lol

1) A little soot like dthquazi said could be adding to this.
2) It's been hella cold in Ontario recently. The cold in general could be contributing to the reduced shrillness of the upshift bang.
3) Exhaust system is getting worn in. My cousin has an IS350 with the F-Sport exhaust and her exhaust has gotten a hell of a lot deeper since she first picked it up.

1Gunner

In my opinion you should feel a difference, as the engine will allow more ignition advance with higher octane = +HP

As for the exhaust, maybe your ears have just climatized to the sound?
I can't believe pipes gunking up or anything such as would be a factor.

munis

I was taking 91 Nitro V from Shell which apparently according to a lot of forums has the least amount of ethanol percentage in Canada, which gets the best mileage for the car. The 94 was from Petro Canada who apparently does dilute the fuel a little bit with ethanol. Even then because of it being 94, technically it should give you a bit more power if the car successfully detects it and advances the timing. Both of the above companies provide tier 1 fuel so you can't go wrong with either of them

But the car to me atleast sounds louder with 94. I will see if I can make a comparison video.

When I pull for hearing the exhaust notes, it is always in Sports+ with all my windows down haha.

Yeah I haven't visited the service dept even once after I got my car. So it definitely isn't any ecu updates for both of us.

About your point 2, shouldn't the opposite be true? Shouldn't the car sound louder in cold because the air is more dense, so you get better combustion out of it? This is all speculation ofcourse. Can you explain why would the car be louder in warmer air? Because that might be it. Last month when the car was really loud, the air actually was warmer. So that would explain it. Now temps are dropping to -10.

I swear the first time I put the car in sports+ mode in downtown Toronto, everyone, I mean everyone within 200m in every direction stopped dead in the street to source out where the gunshots were coming from.

kck77

If your car was manufactured before November 2016, there is an exhaust update from the dealer that supposedly makes the car sound a heck of a lot better as per Rokenr .. he is doing an exhaust comparison video this week on his Instagram between his solar yellow C63S and his Edition 1 C63S that just had the update done .. I am not sure if this update has made its way to North American dealers yet, but worth an ask.

powerrrrr

The buildings downtown does help with resonating the noise quite a bit though.

Also, I don't think the grade of fuel would make a difference, at least in terms of noise with the pops and bangs, which are artificially created by the exhaust system.

Andyroo

Ooh, I hope this is true! I'll see if my local dealer/AMG 'expert' has heard anything... probably not...

5ilver-5urfer

A small skeptical tin-foil hat wearing part of me believes that this is an elaborate ploy by Mercedes to get people to take their car in for an update that secretly makes the car quieter.

5ilver-5urfer

I'm no physicist, but the below post seems like an interesting read that might back up this theory to some extent.

Why do cold metal plates make less noise?

If the backfire sounds less pronounced, it could be that the cold metal is dampening the sound quite a bit. I guess we are both stuck waiting for warmer weather to test this theory

Bueller178

All I know is I absolutely love the PE exhaust and all of it's pops, farts, bangs, crackles and what not.


I certainly hope none of that diminishes over time.

juse

there already was a thread about it and many people were complaining
https://mbworld.org/forums/c43-amg-c...ud-before.html

munis

I am pretty sure my car went into production sometime in October. Is there anyway to confirm this? Also my car is C43.

Read this one already, most of the guys there noticed quiet cars after an update. I did not get any done yet. My temps are really high as well. While pulling in downtown it goes as high as 107C time to time.

Someone in the other thread mentioned something about the 3 sets of valves not opening completely anymore. If this continues, I will probably go back and have the service dept. check that.

newyorktoLA

Is this problem happening to people with Performance Exhaust or people with standard exhaust? I have PE exhaust and was told by my clear bra installer only a month after I bought the car that my car was quieter than an Edition 1 C63S coupe he also did with PE exhaust! I thought no way, but have noticed the exhaust does not crackle and pop nearly as much after a few months.

Production in October 2016.

Sanch

I heard that there is an exhaust software update available. Anyone having issues check with your dealerships.

It hasn't come to Oz yet but Euro/UK do have it available to them.

kck77

Mentioned this above Sanch! Check out Rokenr on Instagram for a comparison video this week between his Solarbeam C63S Coupe and his Edition 1 C63S that just had the update!

Andyroo

Is there an official bulletin on what this is and what it's for? I'm going to ask my local dealer about this ahead of my upcoming service and I know unless I'm armed with all the information, they'll just play dumb...

Edit: Just called the dealer and there are no software updates outstanding. I'm in the UK by the way.

munis

If the crackles and pops are made by excess fuel passed on to the exhaust system, is there anything you can do control this phenomenon and like make more of it happen, haha?

Just asking.

powerrrrr

​​​​​​The noises made by excess fuel in the exhaust system was from overflow in carburated engines when you lift off the gas. The sounds nowadays are made by spraying a tiny amount of fuel into the exhaust system to simulate the noise of the old carburated engines.

As far as I can tell there's no computer tweak to make it do more of that, but I guess you can get rid of the muffler to make your car louder.