3.3TT Extremely sketchy turning - way worse when wet

[xHawaiiToast]

Hey guys, I just created my account and I'm completely new to this forum-world, so please be easy on me. I already posted this question on Reddit and got some pretty harsh comments, even though I just want to find the problem and maybe help other Stinger drivers in the process.

So now to the issue: It started raining a lot in my area a few days ago and my Stinger is acting up like crazy in these conditions.

Almost every time I turn the steering wheel and give a lil bit of gas to take a turn, I can feel some tires spinning/slipping or the AWD-System trying to balance something. I don't know what happens exactly, but something sends clearly audible and feelable vibrations/shocks through the car. My guess is, that it's either one or more spinning/slipping tires, some clutch packs inside the transfer case engaging/releasing or other parts of the AWD-System or the brakes being applied and released a few times in quick succession (Torque Vectoring or something like that).

It feels like an issue with the AWD-System. It's like in a video I found, that shows the same problem on a Jaguar XE-R. I guess many describe it as AWD scrubning/skidding/slipping/whatever.

The Video is called: 2017 Jaguar XE-R Sport 35T AWD scrubbing.

A few days ago, when I drove off my driveway and the rain was pouring like crazy, I had my steering wheel turned in almost all the way to the right and accelerated a little from a standstill. The whole car just shaked (same as described above, but stronger/more/whatever) and didn't move at all. As if every tire was slipping or something like that. I let off the gas pedal, reduced the steering angle and drove off with even less gas than before.

Half an hour ago I was driving to get some food and basically everytime I took a turn or steered to drive left/right while pressing the gas pedal just a lil bit (as described above), I felt the same thing again and again. I had to drive around corners and stuff like a grandma to avoid this issue, but even then it happened some times.

Tbf I don't feel safe at all driving the Stinger in the rain with that issue because I don't want to damage anything and I'm scared af because I don't want to loose control or something like that. It's just ridiculous. I only had one car, a Mercedes C280 W204 RWD, before I got the Stinger and I never had any issues like that. I thought getting a AWD car will be so much better, but now I don't even wanna drive it anymore!

A lil bit of background information:

- My Stinger is a german version and is completely stock.

- The issue only happens when accelerating ( even if I just press the gas pedal ever so slightly) from a standstill and/or at low speeds, below 50 km/h.

- Issue happened at around 10°C - 14°C in heavy or mild rain.

- Issue happens also at much higher temperatures and when it's dry, but it's way less pronounced and happens way less often.

- My front tires are worn a bit more than the rear tires. I don't know why or if that's normal. I bought the car with ~29.000 km and now it has ~31.000 km, so I only drove it for ~ 2.000 km.

- I still have the OE tires installed ( Michelin Pilot Sport 4s 225/40R19 front and 255/35R19 rear)

- The left front tire is worn a bit more than the right one (Rim on the right side was refurbished due to some minor damage/scratches and they put a new tire on it) -> Could this alone lead to the issue?

I made some pictures of my front tires, but I can't post links or pictures, since I'm new... So yeah idk how to show them to you...

I apologize for such a long post. I'm just bad at summarizing and want to give you guys all the information you need to form an opinion. I hope you can help, because I'm just clueless rn...

I've read that this issue was discussed on this thread a few times in some other unrelated thread. I've read through 20 pages on this technical discussion thread that includes the drive train, but I didn't find any posts about this issue. So I apologize for starting a new one if there really are any others, but I really couldn't find anything. There's not even a search function on this website and I didn't find anything through google either...

 

[Snowwhite]

a few questions.

1. how old is your car?
2. how much tread is left on those original tires? and what air pressure are they at?
3. what trim is this? (ie GT, GT1, GT2, GT-S, or whatever Kia sold in Germany...i'm trying to determine if you have the rear mechanical LSD or not. if you know, by all means just mention that.)
4. are you in sport mode when this occurs or comfort/eco? (throttle response is sharper in sport/sport+.)

 

[xHawaiiToast]

a few questions.

1. how old is your car?
2. how much tread is left on those original tires? and what air pressure are they at?
3. what trim is this? (ie GT, GT1, GT2, GT-S, or whatever Kia sold in Germany...i'm trying to determine if you have the rear mechanical LSD or not. if you know, by all means just mention that.)
4. are you in sport mode when this occurs or comfort/eco? (throttle response is sharper in sport/sport+.)

1: Oh sorry, I thought this info would be visible because I put it in my profile. It's a 2023 model.

2: Depends on where I measure. As stated above, my front tires are worn a bit more than the rear ones. And the front left tire is worn a bit more than the right one, because it got changed while the rim was repaired. The mechanic stated that the difference between the used and new tires is within spec and thats why they didn't change both. Tldr: Thread left is about 2-3mm. I don't remember exactly and can't measure rn. I planned on changing tires for next season.
Tire pressure was around 2,3-2,4 bar on front and 2,4-2,5 bar at the back the last few days because the temperatures dropped and I was too busy to fill them up. Before the temperatures dropped I had 2,5 bar in the front and 2,6-2,7 bar in the back. Today I pressured all tires to 2,5 bar at a gas station but somehow the TPS is showing 2,4 bar all around. Guess I will have to inflate them to 2,6 bar tomorrow or so.

3: Tbh I don't have a clue. I asked Kia, searched inside the owners manual, searched through the internet as much as I could and asked on reddit and stuff. I never got a conclusive answere. I would love to answere that but I just can't. Never saw a car thats so hard to get information for. I don't know whats up with kia in this regard. Kia just told me that they think that I have an electronic LSD in the back. But as they just "think" and I've read that a "electronic lsd" can also just mean torque vectoring with some manufacturers, I can't do anything with this info.

4: I drive around in comfort min. 95% of the time and everytime these issues occured I had it in comfort as well. And as stated above I'm VERY sensitive with the throttle, especially when turning at low speeds because I don't want this issue to happen. It just feels so wrong and disgusting that I can't stand it. It feels like the whole car will break apart if it continues. Driving the car around corners has gone to a torture for me tbf.

 

[Thomby]

Tire pressure was around 2,3-2,4 bar on front and 2,4-2,5 bar at the back the last few days because the temperatures dropped and I was too busy to fill them up. Before the temperatures dropped I had 2,5 bar in the front and 2,6-2,7 bar in the back.

Do you have the 19s? I don't think there's any configuration where your rears should be higher than your fronts, and in the case of the staggered 19s you want 38psi front (2.6bar), 36psi rear (2.5bar).

2.3bar is 33psi which is probably fine (softer ride, maybe a little worse mileage) and what plenty of people have as the weather cools or their tires naturally lose a little, but you probably don't want that in the fronts while the rears are still at 38-39psi (2.6-2.7bar).

Have you checked your tire sizes? With greater wear up front, it's possible the prior owner wore out and replaced the rears, and maybe went to a brand/size with enough of a difference in circumference to confuse the AWD or trac/stability control.

 

[xHawaiiToast]

Do you have the 19s? I don't think there's any configuration where your rears should be higher than your fronts, and in the case of the staggered 19s you want 38psi front (2.6bar), 36psi rear (2.5bar).

2.3bar is 33psi which is probably fine (softer ride, maybe a little worse mileage) and what plenty of people have as the weather cools or their tires naturally lose a little, but you probably don't want that in the fronts while the rears are still at 38-39psi (2.6-2.7bar).

Have you checked your tire sizes? With greater wear up front, it's possible the prior owner wore out and replaced the rears, and maybe went to a brand/size with enough of a difference in circumference to confuse the AWD or trac/stability control.

Yes I have the 19's with Michelin Pilot Sport 4S Tires. 225/40R19 front and 255/35R19 rear. My manual states that I should inflate all 4 tires to 2,5 bar for "normal" use and I think it was 2,5 or 2,6 bar front and 2,7 bar rear for transporting heavy stuff or people.

I don't think the issue lies in tire pressure because I've inflated them all to 2,4 bar (actually 2,5 bar at the gas station but TPS shows 2,4 bar all around...) today and nothing changes. Something still "skids" when taking tight turns at low speed.

All tires are the OE ones that came with the car. Only the right front tire was changed as stated above. The owner before me is a good friend of mine and I was sitting for 1000's of km inside the car together with him. I know for a fact that he didn't change any tires. I also measured the diameter of the front tires pretty quick to get a picture of whats going on, but both my measurements came up to 64,4cm from the ground to the top of the tire (used a flat machinist angle to determine the top).

 

[Thomby]

I also measured the diameter of the front tires pretty quick to get a picture of whats going on, but both my measurements came up to 64,4cm from the ground to the top of the tire (used a flat machinist angle to determine the top).

How about the rear diameters, to compare to the fronts?

 

[xHawaiiToast]

How about the rear diameters, to compare to the fronts?

Didn't measure that because the rears look fine and the wear is even. Will measure that after work and tell you what I found.

 

[Snowwhite]

I always run the fronts at a lower pressure than the rears. My older bmws would start wandering on the road if I didn’t, so I just stuck to it. I run 40 psi up front and 44 rear on recommendation from my alignment shop. I don’t have AWD though.

Given your answers, either something is wrong with the coupling for the front axle, or you do have a mechanical LSD and it is locking up, either due to failure, or the wrong fluid (without the LSD additive) is in it. And you are also in dire need of tires if you only have 2mm of tread, that’s the wear bar depth. The rear on this car gets quite lively when the tires are that bald.

 

[xHawaiiToast]

I always run the fronts at a lower pressure than the rears. My older bmws would start wandering on the road if I didn’t, so I just stuck to it. I run 40 psi up front and 44 rear on recommendation from my alignment shop. I don’t have AWD though.

Given your answers, either something is wrong with the coupling for the front axle, or you do have a mechanical LSD and it is locking up, either due to failure, or the wrong fluid (without the LSD additive) is in it. And you are also in dire need of tires if you only have 2mm of tread, that’s the wear bar depth. The rear on this car gets quite lively when the tires are that bald.

Hmm, I've read from many AWD Stinger owners that they have the best results with 2,5 bar front and rear. Also this is recommended by the owners manual, so I will try it and see if I l like it or not.

I will definetly give Kia a call on monday and make an appointment. As for the tires: I intended to get new ones for the next season. It's getting cold now in germany anyway, so I will switch to my winter tires/rims tomorrow. Thats why I didn't really care that the thread is low.

I just thought about it a lil bit again and remembered that the TC-light never came on during the scrubbing, so I guess it's not a traction problem anyway.

 

[Kodiack]

From what you describe it sounds maybe like a transfer case issue.
If it were me I would take out the AWD fuse for a test drive so it reverts to RWD and see if the problem continues.
Removing the fuse will take the vectoring and traction control away from the front drive train.
If its under warranty I would take it to a dealer before all else and ask them to check the transfer case.

 

[xHawaiiToast]

From what you describe it sounds maybe like a transfer case issue.
If it were me I would take out the AWD fuse for a test drive so it reverts to RWD and see if the problem continues.
Removing the fuse will take the vectoring and traction control away from the front drive train.
If its under warranty I would take it to a dealer before all else and ask them to check the transfer case.

I thought about pulling the fuse, but I'd rather not do that. As mentioned in some other thread, the electronic oil pump that regulates the transfer case clutch pressure and lubricates/cools the internal components, gets deactivated when you pull the fuse. There even was an example of someone who pulled the fuse and never put it back in again. He destroyed his transfer in the process...

I will take my stinger to the dealer next week and give you guys an update.