Taycan RWD loud whine from drivetrain?

[Scandinavian]

No whining noise in my 4 CT. I do have tire noise at lower speeds it was more present with my winter tires and more on bad Belgian roads.

Gear changes are present when accelerating fast. Especially when changing from normal to sport under heavier load like going uphill in the mountains. I feel and hear a kind of clunck. At normal speeds I can still feel it when shifting from normal to sport at lower speeds. Had a loaner CT 4 that did the same.

Tyre noise is very low due to the 19 inch Hancock and considerable less than my own 21 inch Good Years.

I also do not feel much of the gear changes in normal. That is not as hard as it is in the Turbo, probably due to the power difference available at full throttle. This is not an issue at all.

The whine and the sound level from the drive train, probably the gears is the issue.

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[Scandinavian]

I have assumed Porsche has probably never worried about hypoid gear mesh noise because they’ve never wanted a quiet engine…. I really understand why they created the fake sound option now.

I do plan on talking to the dealer about this, but I’ve spent a lot of time with gear mesh design, and this is just a really bad gear design coupled with really bad noise isolation.

btw, just for you techy folks. The gear noise is amplified because at lower speeds that create that frequency, standing waves are created between the front and back windshields. I doubt Porsche has ever had to worry about this before, and boy do they have a lot to learn. They should make the fake sound standard, not disable-able, until they can figure this out.

Yes it is very much like gear noise, and it changes when lifting the throttle with regen activated.

It is very irritating on a drive but only when there is speed limits. At higher speeds there are so many other noises from tyres, wind etc that it is not noticeable.

The sound proofing of the cabin and insulation of drive train may be different between models as well. But I suspect that the loaner I have has missed in the specifications or the assembly of motor or gearbox. I could never accept yo have that whine from an electric car.

In videos about the VW ID R and the Mission R you can hear very similar noise whine. But these are stripped out extreme racing cars, not a normal day use car.

I have never heard anything as irritating or loud in any of the electric cars I have tried
Renault ZOE
VW ID4
Mercedes EQC, EQS 580 and 450 RWD, EQE
BMW i4
Audi etron
Mini

Especially the EQS was super silent.

I am really surprised by this and also see that there are owners that have a very quiet car and some have similar observations. So no wiser now.

Not my problem anyhow since I hope my car will be ready today and that is quiet.

 

[McgR]

Tyre noise is very low due to the 19 inch Hancock and considerable less than my own 21 inch Good Years.

I also do not feel much of the gear changes in normal. That is not as hard as it is in the Turbo, probably due to the power difference available at full throttle. This is not an issue at all.

The whine and the sound level from the drive train, probably the gears is the issue.

I think the sound / noise I hear is from the tires. It doesn’t change when shifting gears when switching between normal and sport at lower speeds. And it is better on better road surfaces.


good to hear about your experience with the gear shift sounds like what I feel too.

 

[f1eng]

My RWD has terrible drive train gear noise. I used to be a NVH (noise, vibration and harshness) engineer at GM. I used to specifically work on rear differential hypoid gear noise reduction. I will tell you this RWD car is very bad. I don’t have the fake sound option, and I can clearly tell it is gear noise because I can hear engage, disengage and engage again when I toggle the accerator causing the drivetrain to lash engage the front and back side of the gear teeth.

I have assumed Porsche has probably never worried about hypoid gear mesh noise because they’ve never wanted a quiet engine…. I really understand why they created the fake sound option now.

I do plan on talking to the dealer about this, but I’ve spent a lot of time with gear mesh design, and this is just a really bad gear design coupled with really bad noise isolation.

btw, just for you techy folks. The gear noise is amplified because at lower speeds that create that frequency, standing waves are created between the front and back windshields. I doubt Porsche has ever had to worry about this before, and boy do they have a lot to learn. They should make the fake sound standard, not disable-able, until they can figure this out.

I was also sure from the description it would be gear noise.

Mine doesn't have a particular problem, so it could be a gear tolerance or mounting isolator problem in the car(s) in question.

Before I went into Formula 1 full time I was a noise and vibration R&D engineer too, at David Brown Gear Industries which, back then, made the gearboxes for Royal Navy warships so minimising sonar signature was a significant requirement and I spent time getting the vibration profile signed off on sea trials before the Navy accepted the ship!

The racing gearboxes were very noisy of course, size and weight being more important than NVH on a F1 car!

 

[tomtom901]

@Scandinavian - Could you maybe get the sound on film? Would be interested to hear what you hear, as I don't think my RWD makes a similar sound.

 

[submatrix]

Now I'm curious too. My RWD has always had more motor noise than my Model S did. Even with sport sound off, there is a subdued fake motor sound that the Taycan generates. Wish I could test drive a 4S now, since this apparent issue only occurs in RWDs?

 

[Archimedes]

The suspension is at the same height in normal and sport mode. It is only lowered in sport plus. When I switch from normal to sport at lower speeds I can feel a gear switch.

Depends on the default height you set for normal mode.

As re gears, normal starts in second, whereas sport starts in first and stays there until 49mph if in sport mode (at least in my 4S).

 

[McgR]

Depends on the default height you set for normal mode.

As re gears, normal starts in second, whereas sport starts in first and stays there until 49mph if in sport mode (at least in my 4S).

Thx I didn’t know it was possible to program the ride height for normal and sport mode. I think when I push the AS button it heightens the suspension will give it a try.

I can feel the gear shift when driving at lower speeds and switching from normal to sport or vice vers. It also shift to second when starting in sport and over 75-80 km/h like you mention indeed. But most apparent is when driving down or uphill and switching from normal to sport and forcing the gear change. Than it really is a clunck and driving down hill it is also quite noisy. Maybe it is the regen. Will test again this summer.

 

[Scandinavian]

@Scandinavian - Could you maybe get the sound on film? Would be interested to hear what you hear, as I don't think my RWD makes a similar sound.

I did not get the time to make any recording as Porsche called and had my car ready quite early unfortunately. My observation when driving toPorsche is the following. Sound is very audible up to 50 km/h. Especially loud up to 40 km/h. Since the model did not hve Sport plus it was the same in Normal mode as well as Sport mode. It did not sound the same in Range mode, but I guess it only works in 2nd gear then.

There was not much of a difference when on the throttle or off. And I had regen set at that stage. Slight change in sound level but not much. Going downhill and engaging Neutral the car was silent ( at least that rules out any tyre noise or wheel bearing noise).

I spoke with the Porsche Guru about it and he was going to take the car for a test drive. He did not use that particular car for test drives since it had so few options that there was not much to demonstrate. I will see if he comes back to me later.

Sorry about the rush to get my own car back since I had wanted to do a recording, but schedules got a bit tight!

 

[tomtom901]

Sorry about the rush to get my own car back since I had wanted to do a recording, but schedules got a bit tight!

No worries, just even more curious now

 

[Bennie]

I know about 1 owner who had a similar problem;

https://www.taycanforum.com/forum/threads/deep-hum-between-50-70-km-u-16-23-mph.11825/
https://www.taycanforum.com/forum/t...-h-and-why-we-should-notify-porsche-ag.12368/

Thanks Tom. Indeed, I wrote two threads on the forum. However for me it’s a deep humming sound. Whining suggest that it’s higher?

Porsche Netherlands investigated it two times, but two times: nope… “The sound is noticed but it’s within the margins” was the answer of Porsche AG. Nonsense. What margins? I think they are afraid for a lot of extra claims for replacing the gearbox. Because that‘s where the problematic and annoying sound comes from.

 

[Scandinavian]

Thanks Tom. Indeed, I wrote two threads on the forum. However for me it’s a deep humming sound. Whining suggest that it’s higher?

You are correct it was higher frequency sound not a humming. I would classify my electric sport sound as humming but this was much higher frequency.

A bit more like what you can hear in this video. But not at all that much but the pitch was there. But this is more a track car, so it was expected in that case.

 

[Bennie]

You are correct it was higher frequency sound not a humming. I would classify my electric sport sound as humming but this was much higher frequency.

A bit more like what you can hear in this video. But not at all that much but the pitch was there. But this is more a track car, so it was expected in that case.

Indeed, that’s a much higher sound and certainly different from my deeper humming. Nice video, by the way ?

 

[Marcad80]

To address a couple of the comments above.

the reason you hear it louder at certain speeds is because as the hypoid gear noise changes frequency with speeds it goes in and out of standing wave dimensions of the cockpit. In our studies it was almost always the length of the rear window to the front window, and a standing wave related to a factor of that distance / frequency.

the noise itself is coming from the sliding action hypoid gears make when interacting, and the frequency Is established from the number of teeth on the pinion and the rpm of the pinion. When an order of this frequency crosses a physical dimension in the cockpit a standing wave is generated and watch out decibels….

i used to set up instrument microphones at the drivers right ear, accelerometers on the suspension, tack light on the drive shaft, and then use an FFT analyzer in a dyno to help develop the GM rear wheel drive cars.

This noise is exactly the same noise we were working to eliminate. And I will tell you Porsche has done a horrible job here. Granted the car is very quite, but 1998 GM cargovans managed gearnoise better than this car.

 

[Scandinavian]

To address a couple of the comments above.

the reason you hear it louder at certain speeds is because as the hypoid gear noise changes frequency with speeds it goes in and out of standing wave dimensions of the cockpit. In our studies it was almost always the length of the rear window to the front window, and a standing wave related to a factor of that distance / frequency.

the noise itself is coming from the sliding action hypoid gears make when interacting, and the frequency Is established from the number of teeth on the pinion and the rpm of the pinion. When an order of this frequency crosses a physical dimension in the cockpit a standing wave is generated and watch out decibels….

i used to set up instrument microphones at the drivers right ear, accelerometers on the suspension, tack light on the drive shaft, and then use an FFT analyzer in a dyno to help develop the GM rear wheel drive cars.

This noise is exactly the same noise we were working to eliminate. And I will tell you Porsche has done a horrible job here. Granted the car is very quite, but 1998 GM cargovans managed gearnoise better than this car.

Thanks for the explanation and comments.

I wonder if Porsche install different gearboxes in the different models then . Would not make sense to me, but perhaps the gearbox for the RWD is different to the TT and TTS because of power and torque???

Or alternatively there is some kind of gears in the electric motor? And the electric motor for the RWD could be smaller that the rest of the range???

All my speculation, but a gear sound quite clearly. But surely that should Be similar in all the RWD cars, but it clearly is not. Perhaps due to some small differences in tolerance?

Well not my problem anyhow and I hope they sort it out?

Perhaps something for future RWD buyers to check?? I would never accept an EV with that noise level.

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