Battery dead in a week and weird snorkling noise at idle (unrelated to battery issue)
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Joined: Nov 2016
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From: Toronto, ON
2021 Mercedes C63s AMG Coupe
Battery dead in a week and weird snorkling noise at idle (unrelated to battery issue)
My car does not seem to start if it sits for a week. Happened twice now. My car has Mercedes ME, does the app drain battery to the point the battery dies within a week? Never had this issue with my C43.
On the other hand I am hearing a weird snorkling/ vacuum noise coming from the engine at idle rpm. If you gently tap the accelerator in such a way that the engine rpm does not move, you hear this noise get louder, and then decrease in volume. At the dealership it is the same game of I cannot hear what you are hearing, so just checking if someone else can hear this noise as well?
My friend has a pre facelift and his one does not have this noise.
On the other hand I am hearing a weird snorkling/ vacuum noise coming from the engine at idle rpm. If you gently tap the accelerator in such a way that the engine rpm does not move, you hear this noise get louder, and then decrease in volume. At the dealership it is the same game of I cannot hear what you are hearing, so just checking if someone else can hear this noise as well?
My friend has a pre facelift and his one does not have this noise.
Senior Member
Joined: Sep 2019
Posts: 340
Likes: 82
2019 C63S Sedan
I have a 19 model and don't have the noises you mention.
No battery issues either and my car sits locked for 2-3 weeks every 3 or so months as I go overseas and the battery level shows partly charged in the app then when I'm back . Only time I have seen the battery level at critical is when the car sat for nearly 2months cause I got disqualified for driving for going way to fast on the highway.
No battery issues either and my car sits locked for 2-3 weeks every 3 or so months as I go overseas and the battery level shows partly charged in the app then when I'm back . Only time I have seen the battery level at critical is when the car sat for nearly 2months cause I got disqualified for driving for going way to fast on the highway.
Out Of Control!!
Joined: Nov 2018
Posts: 11,449
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From: San Francisco Bay Area
2019 C63CS
Maybe make a video of the noise, but from the description that's not something that sounds familiar.
As for the battery that depends on how much you drive. A lot of short distance driving doesn't really charge the battery so if you let it sit then it could be possible that the battery ends up dead. Yes, the Mercedes me services drain the battery. The car maintains a permanent connection to the Internet while parked, so just like your smartphone this will slowly drain your battery. Faster if you have a weak signal where you park. You are supposed to get alerts on your phone if the battery goes critical. Also, there's a standby mode in the COMAND system that you can activate. It turns off the Internet connection and everything else that drains the battery and even shows you how long you can leave the car parked w/o the battery going dead. It's described in the owners manual. Only applies to 2019+ models.
During the pandemic I've had my car sit for over a week multiple times. The Mercedes me app showed partially charged for the battery but it never drained. It was clearly getting quite low, though, because while my car was in for Service B in January I started to get critical battery alerts on my phone while they were performing the service. Took a while to fully charge the battery afterwards and I ended up hooking it up to a tender one night to fully charge it again. At the moment it goes between partially charged and fully charged depending on how much I drive. I've been doing regular 250+ miles canyon runs again, so the battery has been mostly fully charged, but if I only do short drives during the week it will eventually show partially charged.
As for the battery that depends on how much you drive. A lot of short distance driving doesn't really charge the battery so if you let it sit then it could be possible that the battery ends up dead. Yes, the Mercedes me services drain the battery. The car maintains a permanent connection to the Internet while parked, so just like your smartphone this will slowly drain your battery. Faster if you have a weak signal where you park. You are supposed to get alerts on your phone if the battery goes critical. Also, there's a standby mode in the COMAND system that you can activate. It turns off the Internet connection and everything else that drains the battery and even shows you how long you can leave the car parked w/o the battery going dead. It's described in the owners manual. Only applies to 2019+ models.
During the pandemic I've had my car sit for over a week multiple times. The Mercedes me app showed partially charged for the battery but it never drained. It was clearly getting quite low, though, because while my car was in for Service B in January I started to get critical battery alerts on my phone while they were performing the service. Took a while to fully charge the battery afterwards and I ended up hooking it up to a tender one night to fully charge it again. At the moment it goes between partially charged and fully charged depending on how much I drive. I've been doing regular 250+ miles canyon runs again, so the battery has been mostly fully charged, but if I only do short drives during the week it will eventually show partially charged.
