Gearbox Issue?
Thread Starter
Junior Member
Joined: May 2024
Posts: 18
Likes: 1
MB C300e S206
Gearbox Issue?
Hi,
I have a 2023 C300e PHEV Estate. I noticed the phenomenon on the car, is that in 1st gear, the gearbox makes a low, but audible uprising sound in proportion to the revs (as I put the pedal and incrase the speed). Like when a spaceship takes off, but very quietly. In higher gears it is no longer audible. Is this normal or a warranty problem? The reason I ask here is that the dealer will probably tell me straight away that it is normal. Even if it is not normal.
Anyway, the shifts are smooth, I don't feel any other problems (except that sometimes you can feel the shifts, especially at low speed, but supposedly this is normal with the 9G tronic)
I have a 2023 C300e PHEV Estate. I noticed the phenomenon on the car, is that in 1st gear, the gearbox makes a low, but audible uprising sound in proportion to the revs (as I put the pedal and incrase the speed). Like when a spaceship takes off, but very quietly. In higher gears it is no longer audible. Is this normal or a warranty problem? The reason I ask here is that the dealer will probably tell me straight away that it is normal. Even if it is not normal.
Anyway, the shifts are smooth, I don't feel any other problems (except that sometimes you can feel the shifts, especially at low speed, but supposedly this is normal with the 9G tronic)
Last edited by Tokra; Sep 29, 2024 at 11:53 AM.
Junior Member
Joined: Apr 2024
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From: Illinois
2025 C300 4Matic Blk/Blk
While I don't have a hybrid Mercedes, my wife has a hybrid Hyundai Tucson. I know that when you first start out, the vehicle has to make a sound while in electric mode to alert those around it that it is moving. Once the combustion engine starts up, it will quit. Not sure if that is what it could be, but I know that is a requirement for that sound. And a spaceship sound is what most people describe it as.
Thread Starter
Junior Member
Joined: May 2024
Posts: 18
Likes: 1
MB C300e S206
While I don't have a hybrid Mercedes, my wife has a hybrid Hyundai Tucson. I know that when you first start out, the vehicle has to make a sound while in electric mode to alert those around it that it is moving. Once the combustion engine starts up, it will quit. Not sure if that is what it could be, but I know that is a requirement for that sound. And a spaceship sound is what most people describe it as.
I am aware of this, but unfortunately it is not the case for me. The sound curves upwards when shifting up, then immediately afterwards drops downwards. The sound is definitely like a gear "slipping" in the gearbox.
The pedestrian protection sound of EVs is not like that (my wife has an Ioniq 5, and it has a distinctive continuous sound).
Junior Member
Joined: Apr 2024
Posts: 58
Likes: 13
From: Illinois
2025 C300 4Matic Blk/Blk
Thank you for your reply!
I am aware of this, but unfortunately it is not the case for me. The sound curves upwards when shifting up, then immediately afterwards drops downwards. The sound is definitely like a gear "slipping" in the gearbox.
The pedestrian protection sound of EVs is not like that (my wife has an Ioniq 5, and it has a distinctive continuous sound).
I am aware of this, but unfortunately it is not the case for me. The sound curves upwards when shifting up, then immediately afterwards drops downwards. The sound is definitely like a gear "slipping" in the gearbox.
The pedestrian protection sound of EVs is not like that (my wife has an Ioniq 5, and it has a distinctive continuous sound).
Thread Starter
Junior Member
Joined: May 2024
Posts: 18
Likes: 1
MB C300e S206
Newbie
Joined: Oct 2024
Posts: 11
Likes: 0
Hi,
I have a 2023 C300e PHEV Estate. I noticed the phenomenon on the car, is that in 1st gear, the gearbox makes a low, but audible uprising sound in proportion to the revs (as I put the pedal and incrase the speed). Like when a spaceship takes off, but very quietly. In higher gears it is no longer audible. Is this normal or a warranty problem? The reason I ask here is that the dealer will probably tell me straight away that it is normal. Even if it is not normal.
Anyway, the shifts are smooth, I don't feel any other problems (except that sometimes you can feel the shifts, especially at low speed, but supposedly this is normal with the 9G tronic)
I have a 2023 C300e PHEV Estate. I noticed the phenomenon on the car, is that in 1st gear, the gearbox makes a low, but audible uprising sound in proportion to the revs (as I put the pedal and incrase the speed). Like when a spaceship takes off, but very quietly. In higher gears it is no longer audible. Is this normal or a warranty problem? The reason I ask here is that the dealer will probably tell me straight away that it is normal. Even if it is not normal.
Anyway, the shifts are smooth, I don't feel any other problems (except that sometimes you can feel the shifts, especially at low speed, but supposedly this is normal with the 9G tronic)
Out Of Control!!
Joined: Nov 2018
Posts: 11,543
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From: San Francisco Bay Area
2019 C63CS
That sounds like what you are hearing is the electric motor between the engine and transmission that assist when you are starting off the line. That would be normal. Once you are moving and the engine is in the powerband it no longer assists. It also assists during shifts to do torque fill or at lower rpm before the turbo spools up, but you probably won't hear it anymore over the road noise above a certain speed.
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Member
Joined: Nov 2018
Posts: 85
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From: United Kingdom
W206 C300e AMG Line Premium Plus with driver assistance package
I believe the oil pumps on these engines are electric. I suspect if you suddenly floor it and the engine hasn’t recently run then it will start circulating oil before suddenly starting the engine at 4000+rpm in order to reduce engine wear.
