Mvxc

Im following this as I’m having the same issue, I have a c450 muffler delete, pops are gone I still get bang on upshift though. They’ve come and gone before. I was thinking maybe gas but I’ve gone through a tank already. The pops sound very muffled like a valve is closed.

W205C43PFL

After the muffler delete, was your vehicle at a dealership for servicing? Like oil change for example. Chances are they might have updated the vehicle's software.

Mvxc

no i haven’t had it taken in. The burbles went away once before but even with mufflers on still. I think my battery is due for change as I keep getting a warning about it but I don’t think that would be an issue? I have a dealer appointment tomorrow, hopefully they can see what it is. But it just sounds so muffled as if something is holding it back from the pops.

Mvxc

i also just added a thing of octane booster. Maybe it’s the gas??? It happened once where once I filled up again it was back to normal but not this time 😞

W205C43PFL

The pops and crackles are controlled by the ECU. It retards the ignition timing to achieve it. Most of us had a more muted car after certain software update which doesn't apply to you. Do you mind sharing the reason why you used octane booster?

W205C43PFL

Battery could have an influence controlling all the sensors and stuff, ours cars have so many electronics that provides data to various systems so you never know.

Mvxc

just got the car back from dealership 😞

W205C43PFL

Sigh : ( I am sorry that it happened. When you told me that you didn't take the vehicle in recently and you told me there was a battery malfunction, I assumed it would be the battery affecting the electronics which provides data used by the ECU to produce the crackles and pops. I wasn't sure there was any form of update to the control module. In many countries, over-the-air updates are pushed to various systems so I am not sure if that is why, although I don't know what kind of updates are pushed over-the-air because it can be a safety issue if for example a corrupted update is installed to the TCU that malfunctions (just as an example). I would assume the OTA updates only affect infotainment and other feature enhancements. EU have strict regulations when it comes to sound and emissions (emissions is the reason why the OPF filter was fitted in) although your C450 wasn't when those restrictions were taken place, besides, it says you live in the USA which is unaffected by these regulations. I am not sure why they have to purposely quiet down your exhaust. Are you able to ask for a detailed explanation from the dealership regarding to this change?

Mvxc

last time I took it to the dealer was probably 5 months ago so I don’t know why I barely got the pops removed like last week is what I don’t understand. I can ask and see what I come up with but I do live in California and I know we have pretty strict emissions standards. I think I’ll get a second opinion though because I get very low pops at under 3k rpm but higher than that I get a small quite abrupt hum when I left off that gas at 4K rpm

W205C43PFL

Strange the problem started to appear long after the last service, I wonder if the car was trying to optimize it self before it decides to follow the instructions given by the new update.

Mvxc

I have another update, after the recent dealer visit I was just going to deal with it and just get a tune pretty soon. But out of nowhere today on my way to work, the pops are back and they’re just as fine as before they were gone. I’m not sure if it was really just the car trying to get use to the summer blend fuel because I did just fill up. The mystery continues... 😄

W205C43PFL

Interesting but thanks for the update. Glad it is behaving the way you like now. Did you switch gas stations or it was always the same one?

couchee53AMG

I’ve been having these same issues, went to my dealer and there are telling my this is normal for this car to work like this after 20k miles, also he tried to say we are putting Low octane fuel- which I would never put in my car!
anyone know where I can get this fixed? I’m in NJ.

SweetAlpaca

I don't know if everyone is aware of this but sometimes when the pops go away is because a sensor triggered something in the ECU and it determines that it is safer to cancel all the pops. I had a turbo sensor that would trigger an ECU code a little while back and every time it did that, the pops would not come up. No check engine light so no way of knowing but using an OBDII scanner you could see it. All I had to do so clear the code and the car would be back to stock with all the pops. I'm sure this may help for a lot of you.

couchee53AMG

Ok will try! Is real odd that my dealership(Paramus)said the car is fine and no issues found! And this is going to happen with this model AMGs, I ask for this in writing abs he just walked away!! THIS IS NOT NORMAL!!

SilverBullet18

bumpity

ferras

hey gents,
i have a c450 90k miles on it. after a month of it being in the body shop, pops and bangs were not happening when in 5-6rpm 40-50 and s+. i’ve heard the ecu maybe reset when battery unplugged but not sure, i’ve heard maybe it needs to ge r back into shape after not being driven, idk please help anyone!