Transmission Whine

[JORDANSILVERNAIL]

2018 Regal GS here. So....I drive with the radio off and the windows and sunroof open most of the time (weather permitting). About 1,000 miles into owning the vehicle (10,000 now) I noticed a significant whine from the transmission. This happens during deceleration by coasting (it happens when applying brakes to decelerate as well, just is much shorter) and when the car reaches 30 mph, it down shifts. THAT is when it starts. At the 30 mph down shift the whining starts and continues until the next down shift. THEN, at the 20 mph down shift it does it again until the next down shift. I work for a Buick Service department, but there are currently no bulletins or recalls for this. I've shown this to the tech we have, he isn't sure. And he doesn't want to hassle with calling TAC. I get it, TAC could have him on the phone for 45 minutes just to tell him they aren't aware of any on going issues. I'm just curious if anyone else experiences this and has taken the car in to have it looked at. Being an employee here just means that my car is dead last and techs don't want to mess with it. I do know that the Yukon and Sierra 8 and 9 speed transmissions actually skip 2nd gear on the down shift, hence the hard bang or extreme slow down (without pressing the brakes) you experience in those vehicles during deceleration. I wonder if the GS skips gears during downshifts as well, and maybe the whining is because of it. Side Note: the whining stops if vehicle is shifted to neutral while decelerating and does it again when reengaged.

 

[Ctrcbob]

Is this a Tour-X with 8 Speed or
a Sportback with a 9 Speed?

Either way, you are in a much better position than the rest of us getting it diagnosed and fixed.

FWIW, I think the AW 8 Speed transmission is a great transmission.

 

[JORDANSILVERNAIL]

Is this a Tour-X with 8 Speed or
a Sportback with a 9 Speed?

Either way, you are in a much better position than the rest of us getting it diagnosed and fixed.

FWIW, I think the AW 8 Speed transmission is a great transmission.

GS 9 speed. Sorry for not Specifying. You would THINK getting my car looked at would be easy, being an employee and all. But that means NOTHING here. it just means that mine gets puts on the back burner and no techs wants to mess with it. Now....if it is something they are familiar with, or a simple diag and fix, then it MIGHT get done in a reasonable amount of time. but I've had a ticket on my car for MONTHS before a tech would touch it in the past. Management just says "you know the policy on employee cars" when i ask if i can get someone to look at it.

 

[Wlepse]

GS 9 speed. Sorry for not Specifying. You would THINK getting my car looked at would be easy, being an employee and all. But that means NOTHING here. it just means that mine gets puts on the back burner and no techs wants to mess with it. Now....if it is something they are familiar with, or a simple diag and fix, then it MIGHT get done in a reasonable amount of time. but I've had a ticket on my car for MONTHS before a tech would touch it in the past. Management just says "you know the policy on employee cars" when i ask if i can get someone to look at it.

I would take it to another dealer. If there is a trans problem you could be doing more damage each time you drive it. But I have had a similar whine that turned out to be a bad alternator. At low rpm it barely made any noise but as speed increased the noise got worse. Do you hear this in all gears or just above a certain rpm?

 

[JORDANSILVERNAIL]

I would take it to another dealer. If there is a trans problem you could be doing more damage each time you drive it. But I have had a similar whine that turned out to be a bad alternator. At low rpm it barely made any noise but as speed increased the noise got worse. Do you hear this in all gears or just above a certain rpm?

it only happens at the times stated in the OP. during deceleration downshifts at the times specified. Ive actually shown my tech and he doesn't know without spending time and effort on it. which is hard to get when you're an employee here

 

[Wlepse]

it only happens at the times stated in the OP. during deceleration downshifts at the times specified. Ive actually shown my tech and he doesn't know without spending time and effort on it. which is hard to get when you're an employee here

If you have already checked fluid level and you are seeing it in several gears I would go to another dealer. Let them diagnose it. My alternator made a whine above a certain rpm regardless of accelerating or decelerating.

 

[Jack GS]

I've noticed that my 2019 GS decelerates promptly when I let off the gas and do not use the brakes. It doesn't coast as much as I'd like it to. The closest I can compare the feel to is the regenerative braking in a hybrid/electric vehicle. Maybe it is downshifting a couple gears.

I have not noticed a whine during deceleration but I will keep my ears open. My guess is it's normal and all you're hearing is the engineered backlash in the gears.

 

[JORDANSILVERNAIL]

I've noticed that my 2019 GS decelerates promptly when I let off the gas and do not use the brakes. It doesn't coast as much as I'd like it to. The closest I can compare the feel to is the regenerative braking in a hybrid/electric vehicle. Maybe it is downshifting a couple gears.

I have not noticed a whine during deceleration but I will keep my ears open. My guess is it's normal and all you're hearing is the engineered backlash in the gears.

That's what I was thinking. That downshift at 30 and 20 mph feels like you're pressing the brakes even though you're not. And that's when the whining starts and continues until the next down shift. I figured if its anything like the 8 and 9 speeds in the Yukon and Sierra, its skipping the next gear on that downshift. But....on the hundreds of test drives I've taken with customers (i like to test drive with my customers and hear or feel what they are experiencing so we are chasing the right problem) I've never heard a whine during those downshifts. I will say this........with the windows up, its BARELY heard, but for someone like me who rides with the radio off and windows down a lot, its loud enough to definitely get ones attention. Being a Service Advisor, its hard for me to ignore sounds that appear out of the ordinary.

 

[NormT]

How many seconds does it engage to whining after a shift? Mechanical or electrical?

The DFCO(decel fuel cutoff) shuts off the engine and freewheels to save fuel. In my old 2016 Envision the DFCO would charge the battery at the same time.

Can you monitor the voltage during this event?

What about manual mode coming to a stop?

 

[JORDANSILVERNAIL]

How many seconds does it engage to whining after a shift? Mechanical or electrical?

The DFCO(decel fuel cutoff) shuts off the engine and freewheels to save fuel. In my old 2016 Envision the DFCO would charge the battery at the same time.

Can you monitor the voltage during this event?

What about manual mode coming to a stop?
[/QU

How many seconds does it engage to whining after a shift? Mechanical or electrical?

The DFCO(decel fuel cutoff) shuts off the engine and freewheels to save fuel. In my old 2016 Envision the DFCO would charge the battery at the same time.

Can you monitor the voltage during this event?

What about manual mode coming to a stop?

Only in auto. The Regal GS does not have DFCO. It only happens at the 30 and 20 mph downshift. And its IMMEDIATE, and lasts until the next down shift. Its not electrical. The whine stops when trans in shifted to neutral. And starts if shifted back into drive. Being a Service Advisor, I've gone through all the possibilities in my head, and im pretty sure its from the Transmission.

 

[NormT]

Only in auto. The Regal GS does not have DFCO. It only happens at the 30 and 20 mph downshift. And its IMMEDIATE, and lasts until the next down shift. Its not electrical. The whine stops when trans in shifted to neutral. And starts if shifted back into drive. Being a Service Advisor, I've gone through all the possibilities in my head, and im pretty sure its from the Transmission.

Can you monitor battery voltage during the event?

If you get the tech to monitor the shifting characteristics or someone with datalogging software like HPTuners you might be narrow it down. But as you know until something breaks the dealership won't touch it.

How many miles?

 

[JORDANSILVERNAIL]

Can you monitor battery voltage during the event?

Yes, and it stays right around 14 volts. The only time voltage drops in this GS is when auto stopped. When it hits 10 volts, the car starts back up. Not gonna be related to thw whine. My Trans tech at the dealer i work for said "its transmission, but i don't know what it would be without spending time and effort, possibly calling TAC or performing a tear down"

 

[liuby33]

If it is only one gear in which you get the noise, then my wild guess is that something is grinding mechanically in that specific gear, which is bad news for any machine.

Pretty sure you've tried this already since you are more technical than most of us, but if you have done it please share your experience:
When you decelerate to a point the noise shows up, quickly throw into Manual to lock that gear in, see which gear it is, and drive (accel and decel) to see if the noise continues.

I'd say that if noise only takes place in this gear but not in others (test by shifting up/down), then it is safer to inspect in detail what's wrong with this gear.

 

[LARRY70GS]

Not being familiar with newer transmissions, I can tell you other older transmissions can whine from transmission oil pump problems OR filter assemblies that are not sealed up properly. Have you ever changed the transmission oil? Sometimes, it pays to check the simple stuff first.

 

[liuby33]

I paid close attention and did notice some high pitch whine at lower speeds, especially as you mentioned after downshifting at 48kpm (30mph). However, being a mechanical engineer myself I'd say the level of noise is nothing for me to raise concern about, and if I open any window it is not audible. Not sure if we are experiencing different phenomena or if we have different sensibility.

 

[JORDANSILVERNAIL]

I paid close attention and did notice some high pitch whine at lower speeds, especially as you mentioned after downshifting at 48kpm (30mph). However, being a mechanical engineer myself I'd say the level of noise is nothing for me to raise concern about, and if I open any window it is not audible. Not sure if we are experiencing different phenomena or if we have different sensibility.

It's the opposite for me. If I open the windows, it becomes more audible. Especially if I'm rolling by a wall, fence, or other cars. the sound bounces off those objects and makes it VERY noticeable.

 

[liuby33]

It's the opposite for me. If I open the windows, it becomes more audible. Especially if I'm rolling by a wall, fence, or other cars. the sound bounces off those objects and makes it VERY noticeable.

This doesn't encourage safe driving but if there's a video it would be nice 🙂

Normally if a sound is picked up by cellphone mic it is quite a lot for human ears. If opening the window amplifies the sound it does mean that the sound is more external. Maybe it's Toronto's ambient noise that covers it good.

BTW I reckon it is gear 4 in my case.

 

[MelsRegal]

Did you actually pay for this car at the dealership you currently work for or is this a dealership owned vehicle?
If you paid for this car there is noway you should be treated as a second class vehicle owner.
If you did pay for it, have you been there long enough to go directly to the owner of the dealership or would this cause an issue with your continued employment?

 

[JORDANSILVERNAIL]

This doesn't encourage safe driving but if there's a video it would be nice 🙂

Normally if a sound is picked up by cellphone mic it is quite a lot for human ears. If opening the window amplifies the sound it does mean that the sound is more external. Maybe it's Toronto's ambient noise that covers it good.

BTW I reckon it is gear 4 in my case.

yep, im pretty sure its the downshift to 4th. pretty sure it goes from 6th to 4th. It also seems to downshift from 3rd to 1st. Which is the same as the Yukons and Sierras. And thats when the whine occurs. The thing is, I've never heard this whine before when test driving with customers. At the very least, I'm glad I'm raising awareness.

 

[JORDANSILVERNAIL]

Did you actually pay for this car at the dealership you currently work for or is this a dealership owned vehicle?
If you paid for this car there is noway you should be treated as a second class vehicle owner.
If you did pay for it, have you been there long enough to go directly to the owner of the dealership or would this cause an issue with your continued employment?

It's my car that i purchased through the dealer i work for. unfortunately, its just kinda how it works being an employee at a dealership. If i go to the owner, its gonna cause problems. If i complain to GM or bomb a survey, I'll likely no longer have a job. now.....if my car just breaks down, it becomes more of a priority, only because they don't want to pay for a ton or rental car time. You would think that being an employee that it would be a snap of the fingers, but it couldn't be further from the truth.