FAQ: Vibration under braking: warped rotors? NO!

[itguy61]

Khartunerz had them. I think the EOM replacements are the Gyrodisc, Stoptech and Centric pads.

 

[turboAWD]

Edit: never mind, figured it out.

 

[SpaceGhost]

Whether this issue manifests is highly dependent on driving style, roads used, etc. The pads and rotors are the same on all USDM Stinger GTs. If someone does not have the issue, they don't drive aggressively enough or on challenging enough roads to heat up the brakes sufficiently. If I went and drove their car, guaranteed I could get pad deposits on the rotors within an hour..

I have two stingers a 2018 black GT2 and a 2019 red GT1. I bought the GT1 in March it is the one with the brake issues. The dealer where I bought the GT1 had a giveaway the GT2 which I won in May. My wife doesn't like black cars so I gave her the red one and I've been driving the black one.

I was the only driver when the GT1 first had brake pulsing since around 1K miles. I am the only driver of the black one which has over 2K miles and no pulsing and I can tell you for sure it isn't going to pulse. One car is fine the other is not same driver and same roads. You are wrong!

The rotors and pads were changed on the GT1 and it's rough at high speeds makes a rrrrrrrrr noise, the brakes squeak at low speed. The pulsing is going to come back. I think it's the calipers not the rotors/pads

 

[itguy61]

You might have bad calipers but I the problems here are not calipers. Caliper problems tear brakes up, chew up rotors and pads.

 

[SpaceGhost]

Just kind of tiring reading about bedding brakes and driving aggressive when I have had so many cars with no issue including another one of this exact same car so no bedding brakes and aggressive driving are not the solution. fake news

 

[itguy61]

Just kind of tiring reading about bedding brakes and driving aggressive when I have had so many cars with no issue including another one of this exact same car so no bedding brakes and aggressive driving are not the solution. fake news

I would ignore the posts you are tired of reading about, don't let it bother you. Others including myself have had this issue repeatedly and as of right now the vast majority of the evidence points to pad compound putting deposits on rotors and causing vibration. If you are having a different issue I hope you are able to resolve it easily!

 

[MerlintheMad]

I have two stingers a 2018 black GT2 and a 2019 red GT1. I bought the GT1 in March it is the one with the brake issues. … The pulsing is going to come back. I think it's the calipers not the rotors/pads

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I would ignore the posts you are tired of reading about, don't let it bother you. Others including myself have had this issue repeatedly and as of right now the vast majority of the evidence points to pad compound putting deposits on rotors and causing vibration. If you are having a different issue I hope you are able to resolve it easily!

It's weird that the newer of the two cars has the poor feeling brakes. Is it possible that Kia is still getting the OE pads without having done a damned thing to address the depositing incidence? I don't suspect the calipers. From all that has been shared here, I still suspect a crappy set of pads. And if it were my issue, I'd try an aftermarket set.

 

[SpaceGhost]

It's weird that the newer of the two cars has the poor feeling brakes. Is it possible that Kia is still getting the OE pads without having done a damned thing to address the depositing incidence? I don't suspect the calipers. From all that has been shared here, I still suspect a crappy set of pads. And if it were my issue, I'd try an aftermarket set.

Don't forget the newer one with the bad brakes got a new set of rotors and pads. It was perfectly smooth for about 500 miles but the warping is now coming back (or roughness). I also had a similar experience with an Infiniti the brakes were serviced under warranty several times they covered them as a known issue for 24K miles. Once I had to pay I took it to an independent shop the mechanic said that the caliper was sticking and he sanded and greased something (I forget) and thought it was fixed. Not sure if it was that or he probably used a non oem rotor/pad but either way the problem was fixed and never returned.

I don't know what it is but if you are reading this it's not that you are driving the car wrong. It's not that you didn't bed the brakes. I don't know what it is but not those two because I have two of them. The one that got new pads I did the bedding procedure when I picked up the car. It made no difference at all.

 

[Legendsk]

In case there may be a relationship with the point(s) of this thread -

I haven't really found any good information on specifically how the EPB system works on a GT2. Is the electronic parking brake actually a part of the Brembo brakes? The owner's manual mentions that when EPB is applied or released, "you may hear the whine of the parking brake electric motor", so wherever it is and whatever it does, apparently it is not operated by precisely the same process that the brake pedal uses?

How does Auto Hold play into this (if at all)? Does AH use the brakes, EPB, or transmission to hold the car in place? If you are using AH does this really wind up doing the same thing as getting the brakes hot, then pulling up to a stop light, pressing on the brake pedal and holding the car and creating the problems described in this thread? Instinctively it feels like activating the AH by stopping and 'firmly' pressing the brake pedal enables AH and when you lift your braking foot, nothing happens - as though AH was continuing to hold the brake system just as though your foot was still pressing on the pedal, using the same brake process and thereby doing what this thread says, don't do?

Can someone explain these two systems in detail (the OM certainly does not), or point me to the information. Thanks

 

[D.J.]

In case there may be a relationship with the point(s) of this thread -

I haven't really found any good information on specifically how the EPB (Electronic Parking Brake) system works on a GT2. Is the electronic parking brake actually a part of the Brembo brakes? The owner's manual mentions that when EPB (Electronic Parking Brake) is applied or released, "you may hear the whine of the parking brake electric motor", so wherever it is and whatever it does, apparently it is not operated by precisely the same process that the brake pedal uses?

How does Auto Hold play into this (if at all)? Does AH use the brakes, EPB (Electronic Parking Brake), or transmission to hold the car in place? If you are using AH does this really wind up doing the same thing as getting the brakes hot, then pulling up to a stop light, pressing on the brake pedal and holding the car and creating the problems described in this thread? Instinctively it feels like activating the AH by stopping and 'firmly' pressing the brake pedal enables AH and when you lift your braking foot, nothing happens - as though AH was continuing to hold the brake system just as though your foot was still pressing on the pedal, using the same brake process and thereby doing what this thread says, don't do?

Can someone explain these two systems in detail (the OM certainly does not), or point me to the information. Thanks

The EPB is completely separate from the AH.
The EPB is electric and holds the 2 rear wheels stopped using drums inside the rear disks.
The AH feature is as you describe - piggy backed onto the hydraulic system and simulates you pressing the brake pedal and holding. The AH feature is the same system that will apply the brakes for you when you have smart cruise control activated and the car in front of you decelerates (Hydraulic - same as pressing the brake pedal, all 4 brakes are applied).

The EPB actuator is circled in this attached image. Nothing to do with the Brembo calipers

 

[Legendsk]

Thanks. As expected then, using AH will in fact be doing the same thing as the posts above said DON"T DO to avoid the deposit problems being diagnosed as warped rotors.

 

[MerlintheMad]

The EPB (Electronic Parking Brake) is completely separate from the AH.
The EPB (Electronic Parking Brake) is electric and holds the 2 rear wheels stopped using drums inside the rear disks.
The AH feature is as you describe - piggy backed onto the hydraulic system and simulates you pressing the brake pedal and holding. The AH feature is the same system that will apply the brakes for you when you have smart cruise control activated and the car in front of you decelerates (Hydraulic - same as pressing the brake pedal, all 4 brakes are applied).

The EPB (Electronic Parking Brake) actuator is circled in this attached image. Nothing to do with the Brembo calipers

I dithered between "Informative" and "Winner". That pic is long in coming. We've gone back and forth with this question for months. What took (somebody) so long? Thanks for clearing this up.

 

[D.J.]

Additionally...

#16 here - (on the 2nd image) - is the actuator circled in the image I posted in post #310.
xxxxx (I'm not able to post a link?)

If you ctrl+F - PN xxxxxxx that is the actuator (#16 for the brembo parts list) - the SECOND image from this site.

 

[MerlintheMad]

Additionally...

#16 here - (on the 2nd image) - is the actuator circled in the image I posted in post #310.
xxxxx (I'm not able to post a link?)

If you ctrl+F - PN xxxxxxx that is the actuator (#16 for the brembo parts list) - the SECOND image from this site.

Super!
You can post links after you're no longer a Newish Member, 15 posts threshold, I believe.

 

[D.J.]

Thanks. I'm a super noob to this forum I suppose.

 

[Snatchell]

This may have been covered but over torqued lug nuts can also cause warping of rotors. I had my brakes "fixed" by Kia at about 12,000 miles. Now I'm at 17,000 and the issue is back. So frustrating! They should be 79 - 94 lb/ft. Suggestions? I have a feeling they will say I'm hard on the brakes but I'm certainly not. No race track visits and no hard stops/emergency stops. I'm pissed!

 

[Snatchell]

https://www.automobilemag.com/news/2018-kia-stinger-gt-long-term-test-update-2/

Look towards the middle of the article. A test driver had the warped brakes issue at 11,000 miles. He called Kia and they said they were aware of the issue. Hmmm...

 

[OnTheRoad]

https://www.automobilemag.com/news/2018-kia-stinger-gt-long-term-test-update-2/

Look towards the middle of the article. A test driver had the warped brakes issue at 11,000 miles. He called Kia and they said they were aware of the issue. Hmmm...

Same issue here. Told the service technician that the online forum was leaning towards pad residue causing the pulsing/vibrating. He said the rotors were in fact warped (6000 miles on car) based on measuring the displacement or some such. I forget the exact measurement number that he mentioned, but he said it was borderline between cutting/resurfacing and replacing, so he called the Kia tech line for approval to replace them. They OK'ed full replacement based on the measurement that he gave them.

He said that this has been common with Stinger rotors and the times that he cut rather than replaced them, the problem has sometimes come back for some owners. TBD how the replaced rotors feel next week. I'll definitely be bedding them this time though, which hopefully will decrease the chances of this issue reoccurring.

 

[MerlintheMad]

Same issue here. Told the service technician that the online forum was leaning towards pad residue causing the pulsing/vibrating. He said the rotors were in fact warped (6000 miles on car) based on measuring the displacement or some such. I forget the exact measurement number that he mentioned, but he said it was borderline between cutting/resurfacing and replacing, so he called the Kia tech line for approval to replace them. They OK'ed full replacement based on the measurement that he gave them.

He said that this has been common with Stinger rotors and the times that he cut rather than replaced them, the problem has sometimes come back for some owners. TBD how the replaced rotors feel next week. I'll definitely be bedding them this time though, which hopefully will decrease the chances of this issue reoccurring.

I'm not buying the "warped" diagnosis. The rotor must be on crooked so it wobbles.

 

[OnTheRoad]

I'm not buying the "warped" diagnosis. The rotor must be on crooked so it wobbles.

That did sound more like what he was saying based on that measurement. I don't recall actually hearing the word "warped." Now why that can't be fixed with a simple realignment is beyond me.