Stinger GT braking vibration

[Royalstorm]

https://youtu.be/qibmtK7NKYY

Here?s a quick video of the sound for anyone who?s interested.

 

[Royalstorm]

The problem you are describing is not happening while you are applying the brakes, so how is it a braking vibration? Warped rotors, which is what 99% of all braking vibration is caused by, will vibrate more the faster you are going and the harder you brake. The opposite of your situation. How are you determining the brakes are causing the issue? It is much more likely to be engine or transmission based on your description, or, the ISG is still functioning to some extent even though you think it is off or it is in fact off.

I suppose ?braking vibration? is an inaccurate description. However the vibration does seem to directly correlate with the use of the brakes which is why I still think it?s a brake-related problem. I agreed that the rotors are unlikely an issue for the reasons you stated above. But the fact that it occurs the moment the brakes are even lightly released and also more subtly when they are again applied seems to suggest some component of the braking system. The video I posted illustrates the sound when the brakes are slowly released from a complete stop.

https://youtu.be/qibmtK7NKYY

 

[mldavis2]

Could be a servo in the automatic braking system. Have it checked.

 

[Royalstorm]

Another update:
No vibration when driving from a cold start. I turned on the ?auto-hold? feature to see if this could be involved and this initially was working fine. After 5 minutes of driving, immediately after coming to a stop, auto-hold symbol went from white to green (normal function) and at that moment the same hum/vibration that I have described occurred. Then while continuing to drive, after multiple complete stops, the auto-hold would fail to engage (white light would not transition to green). Vibration sound continued after each transition from stop as described before. So now I?m wondering if it has something to do with the programming of the auto-hold. I tried turning the auto-hold on and off but it continued to fail to engage once I?ve driven for 5-10 minutes.

Has anyone else noticed this regarding the auto-hold after prolonged driving?

 

[Kazz]

Never used it, but thought you had to use it at each stop? I just don't see a use for it. Hope this get's figure out soon!

 

[mldavis2]

See my comment on another thread -- duplicate post. The Auto-Hold is for holding the car on a hill so you don't roll backwards when starting from a stop. I don't think it's supposed to be on all the time, just when you need it on a hill. I suspect the vibration is the electric parking brake turning on/off.

 

[Royalstorm]

Auto-hold is working now. Apparently you need to depress the brake pedal passed the point where the car comes to a complete stop to activate the auto-hold.

 

[mldavis2]

Yes, there seems to be a two-position switch for the brake pedal. One high position (light pressure) will activate brake lights and disengage the cruise. The lower (harder) position controls the Stop/Start function and apparently the Auto-hold (which I would never use after years of driving stick shifts.)

 

[Marc Collins]

Yes, there seems to be a two-position switch for the brake pedal. One high position (light pressure) will activate brake lights and disengage the cruise. The lower (harder) position controls the Stop/Start function and apparently the Auto-hold (which I would never use after years of driving stick shifts.)

Sounds like brilliant design to me. Very glad it works that way. I don't want to fiddle with switches or have the car "brain" try to figure out what I want to do, especially with ISG. Simple ability to control it with a change in pressure.

 

[Royalstorm]

Update:
I took the car in today to the dealership. I was able to replicate the vibration/hum for the technician after a short drive. He did inspect the brakes and felt that the hum is normal and secondary to the brake pump. I asked if they would let me take one of the other stingers for a drive to compare and was able to take a GT1 for a 5 mike highway trip. After multiple stops, I couldn?t appreciate any hum or vibration, so I have a hard time believing this is normal. I called Kia directly to open up a case. Any other recommendations?

 

[Danny_O]

Update:
I took the car in today to the dealership. I was able to replicate the vibration/hum for the technician after a short drive. He did inspect the brakes and felt that the hum is normal and secondary to the brake pump. I asked if they would let me take one of the other stingers for a drive to compare and was able to take a GT1 for a 5 mike highway trip. After multiple stops, I couldn?t appreciate any hum or vibration, so I have a hard time believing this is normal. I called Kia directly to open up a case. Any other recommendations?

Contacting Kia customer service directly will be your best bet.

 

[Steve O]

BS Royalstorm. The brakes should feel as smooth as glass. No grinding, no pulsing, no shimmying, NO NOTHING! My dealer checked and said the rotors are warped and he ordered replacements. I asked how could Brembo brakes warp? Usually that is due to overheating and undersized rotors that I would expect on a FORD. He said maybe the wheels were over-torqued when the spring kit was installed. No problem. He's replacing both front rotors under warranty.

 

[Royalstorm]

I?m suspicious too. The only difference is I don?t notice any sounds or vibrations when braking. It?s only after coming to a complete stop and then letting off the brake pedal that I hear the hum and feel the vibration. How many miles did you have when your issues started?

 

[Chi-Guy]

[MENTION=675]Royalstorm[/MENTION] did the adviser provide a reason why you weren't able to replicate the noise on the other Stinger? Are you able to take it to another dealer for a second opinion?

 

[Royalstorm]

No, they had no explanation other than saying that the stingers are so new that there is little information currently available about potential problems. They said they had to wait to hear back from Kia technical support before they would pursue replacing the brake pump or investigating further. I reintegrated my concern about the inability to replicate the sound on the GT1. I then called Kia directly and gave them my VIN and explained the problem. They said that since this is considered a premium model, they would be investigating further (whatever that means). Unfortunately there are no other dealerships even close to me, and even if I could drive to the nearest over a 100 miles away, I?m not sure if I?d want to until I can figure out what?s going on.

It?s almost more disconcerting that it appears after higher speed driving. The technician said that was because the pump has to work harder at higher speeds. Yet the GT1 I drive was as quiet as could be...

 

[kwikia]

I?m suspicious too. The only difference is I don?t notice any sounds or vibrations when braking. It?s only after coming to a complete stop and then letting off the brake pedal that I hear the hum and feel the vibration. How many miles did you have when your issues started?

That does not sound right at all, my brakes make zero noise whatsoever.

 

[mldavis2]

Is the vibration with the Auto Start/Stop on or off?

 

[Royalstorm]

Is the vibration with the Auto Start/Stop on or off?

I have both the idle stop/go and auto-hold off (yellow light on Idle stop/go is illuminated). I?ve tried with it both on and off and it makes no difference. The hum/vibration is short if I quickly let off the brake pedal after a complete stop but is drawn out if I release it slowly. There is also a very brief sound when brake is applied right before the wheels stop turning. Here?s a link to hear the sound. It?s hard to replicate but you can definitely hear it.

https://youtu.be/qibmtK7NKYY

 

[Mops]

I have both the idle stop/go and auto-hold off (yellow light on Idle stop/go is illuminated). I?ve tried with it both on and off and it makes no difference. The hum/vibration is short if I quickly let off the brake pedal after a complete stop but is drawn out if I release it slowly. There is also a very brief sound when brake is applied right before the wheels stop turning. Here?s a link to hear the sound. It?s hard to replicate but you can definitely hear it.

https://youtu.be/qibmtK7NKYY

Is it the sound at the very beginning of the video?

 

[Royalstorm]

Is it the sound at the very beginning of the video?

Yeah, almost right after the video starts. Mid-pitch hum for a second. I recorded long enough to hear it twice. I was trying to hold the phone against the armrest since that?s where the vibration can be felt but then I got the rubbing noise from the console too.