Hissing whining sound on acceleration

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wizardj

New member
Joined
Jan 20, 2024
Messages
3
Location
France
Hello from france, new on the forum
So the class b has about 100 to 120 kms autonomy , I don't have range plus on this 2016 model and it has 113000kms .
No warning signals or errors onboard, and the car is in guarantee untill February.
Now when I accelerate I hear this high pitch sound when on zero no sound only on acceleration and when recharging the sound seems minor normal, now I have driven other electric cars I don't get this sound on acceleration, i tried to call Mercedes about this if it was motor problem since I have read about similar issues, they told me I have to go get the car checked and if there is a problem they will if the participate in fixing, called the local dealership and they never called me back , one problem being it seems no one knows this model or is qualified in the south of France on this type of véhicule.
I will upload a video this week so people can hear the noise I am talking about.
One question is Because this is my mother's new car to drive around, does it make high pitch sound when you accelerate? Is it normal ? The seller said it was the sound of the electric car, thinking I never had an electric car before , my two other electric cars experience are pretty much silent.
If any one knows of some expert in south of France, or how to contact mb or tesla for motor guarantee,
Or just how long can we drive with this hissing sound before car or motor needs to be replaced. Any help welcome , I ve never used mb guarantee either , so no idea about protocol.
Thank you and other than that it's a lovely powerful drive , I'm impressed by this car outside the short range In my case a solid 100kms but it's winter , I was hoping for 150/160kms , so could it be motor friction that looses the range or used batteries ?
Any hack to change the panel or to get range plus update welcome . Best greetings.
 
Hello from france, new on the forum
So the class b has about 100 to 120 kms autonomy , I don't have range plus on this 2016 model and it has 113000kms .
No warning signals or errors onboard, and the car is in guarantee untill February.
Now when I accelerate I hear this high pitch sound when on zero no sound only on acceleration and when recharging the sound seems minor normal, now I have driven other electric cars I don't get this sound on acceleration, i tried to call Mercedes about this if it was motor problem since I have read about similar issues, they told me I have to go get the car checked and if there is a problem they will if the participate in fixing, called the local dealership and they never called me back , one problem being it seems no one knows this model or is qualified in the south of France on this type of véhicule.
I will upload a video this week so people can hear the noise I am talking about.
One question is Because this is my mother's new car to drive around, does it make high pitch sound when you accelerate? Is it normal ? The seller said it was the sound of the electric car, thinking I never had an electric car before , my two other electric cars experience are pretty much silent.
If any one knows of some expert in south of France, or how to contact mb or tesla for motor guarantee,
Or just how long can we drive with this hissing sound before car or motor needs to be replaced. Any help welcome , I ve never used mb guarantee either , so no idea about protocol.
Thank you and other than that it's a lovely powerful drive , I'm impressed by this car outside the short range In my case a solid 100kms but it's winter , I was hoping for 150/160kms , so could it be motor friction that looses the range or used batteries ?
Any hack to change the panel or to get range plus update welcome . Best greetings.
I think you need to schedule a visit to the dealer. I am in the US so EPA range is 87 mi standard (140km) and 105 mi with range extension (168km). The battery is guaranteed for 8 years but is supposed to have a new desiccant filter installed every year. While there have them diagnose the whine. I bet it might be the transmission bearings. You want to have the bearings replaced, you normally don't need a new unit, before the damage is too great to repair.
 
I think you need to schedule a visit to the dealer. I am in the US so EPA range is 87 mi standard (140km) and 105 mi with range extension (168km). The battery is guaranteed for 8 years but is supposed to have a new desiccant filter installed every year. While there have them diagnose the whine. I bet it might be the transmission bearings. You want to have the bearings replaced, you normally don't need a new unit, before the damage is too great to repair.
Thank you for the information about the transmission bearings , it might be that I will update with a video. Best greetings.
 
I second the gearbox bearings. There are two rather basic bearings 6207 and 6208 on the incoming side and it spins at the same RPM as the rotor, up to 12000. They wear out and cause this whining noise, it's the same for all early Teslas and the Toyota RAV4 electric. Search for "Tesla million noise" on Youtube.
The good news is that the drive unit can be opened at the gearbox without opening the motor part.
You need the two bearings above, 2 litres of transmission fluid and two seals for the axle shafts (same size as BMW and other brands). The bearings are usually only available as 2RS so the mechanic will need to pry off the dust covers on both sides as the bearings are lubricated by the transmissions fluid itself.
I've got this fixed and my car is (near) silent again. 167000km currently.

Forget about the Mercedes-Benz dealerships: the only repair they will offer you is a replacement of the complete drive unit at your cost (way over €10,000). Find a garage the repairs Teslas, they will know everything about the B-Class and will be able to repair it for you. It is the same drive unit (motor) as the one in the early Tesla model S cars.

If you know a good mechanic, they can also fix it, there is quite a lot of info online. I'm happy to help with any details. My mechanic said fixing this motor was 10x easier than any petrol or diesel engine.
 
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A bit of additional info: the drive unit is not the same as Model S, it merely has a lot of interchangeable parts. In the B250e and RAV4 EV, it's mounted reversed, the gears have their angle reversed, the oil pump is reversed, the case halves are different (to accommodate electric Park), and the MB has an additional interface board on the inverter side. You can't, for example, buy a Model S drive unit and install it in your MB, not even close!

The motor end is pretty much identical (troublesome coolant seal, troublesome rotor bearings, Aegis ring on our early units) but the gearbox has few interchangeable parts. And the brgs that fail are the rotor bearings, not gearbox bearings; early production units had insufficient rotor induced current grounding via an Aegis ring ("whisker brush"); rebuilds get ceramic ball bearings for the rotor, moving the rotor grounding to the gearbox pinion bearing and pinion gears, which is why that first gearbox bearing is typically replaced when the rotor is out for new bearings or seal surface repair, and why the pinion gear sometimes has pitting.

Howard Cheug (Seattle area), Johan (Calif.) and many others have been deep into the LDU and have extensively documented it, as possible with so many variations by Tesla over the years. Neither Tesla, Toyota, nor MB are interested in supporting these "old" vehicles, so it's on us to do what we can.
 
I think you need to schedule a visit to the dealer. I am in the US so EPA range is 87 mi standard (140km) and 105 mi with range extension (168km). The battery is guaranteed for 8 years but is supposed to have a new desiccant filter installed every year. While there have them diagnose the whine. I bet it might be the transmission bearings. You want to have the bearings replaced, you normally don't need a new unit, before the damage is too great to repair.
Just to reduce anxiety: 140km might be achievable in a mild or warm weather, 100-120km is perfectly good in January, in France. it will be more around the 130-140km range in summer.
 
I second the gearbox bearings. There are two rather basic bearings 6207 and 6208 on the incoming side and it spins at the same RPM as the rotor, up to 12000. They wear out and cause this whining noise, it's the same for all early Teslas and the Toyota RAV4 electric. Search for "Tesla million noise" on Youtube.
The good news is that the drive unit can be opened at the gearbox without opening the motor part.
You need the two bearings above, 2 litres of transmission fluid and two seals for the axle shafts (same size as BMW and other brands). The bearings are usually only available as 2RS so the mechanic will need to pry off the dust covers on both sides as the bearings are lubricated by the transmissions fluid itself.
I've got this fixed and my car is (near) silent again. 167000km currently.

Forget about the Mercedes-Benz dealerships: the only repair they will offer you is a replacement of the complete drive unit at your cost (way over €10,000). Find a garage the repairs Teslas, they will know everything about the B-Class and will be able to repair it for you. It is the same drive unit (motor) as the one in the early Tesla model S cars.

If you know a good mechanic, they can also fix it, there is quite a lot of info online. I'm happy to help with any details. My mechanic said fixing this motor was 10x easier than any petrol or diesel engine.
Win, thank you for sharing this, it would be great to share more information maybe for the diy guys out there, not a mechanic but might it give it try to fixing it myself or at least understand better , cheers
 
Win, thank you for sharing this, it would be great to share more information maybe for the diy guys out there, not a mechanic but might it give it try to fixing it myself or at least understand better , cheers
I'm happy to help anyone but all the info I gathered is already available online in this forum, the Facebook group https://www.facebook.com/groups/bclasselectric and various Tesla forums. Youtube has repair videos too, I think for the Rav4.
I was consulting to someone from Hungary who did the exact same repair so I had a confirmation beforehand that the two bearings indeed fix the milling noise, and that the rotor side does not need to be opened for this.
 
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