2018 Denali acts weird in rain?

[Doubeleive]

This sounds to me like hydroplaneing with bad shocks. The rear shocks could be causing front to back motion. Have those shocks checked out.

with brand new tires? unlikely, as much as I don't care for michelin's that shouldn't happen even if the shocks were totally wasted
or mom & pops are blasting that thing wot in the rain

 

[Doubeleive]

this is death wobble, his diagnosis is not identical to the 2018 with electric steering but the end result from worn parts or misalignment are the same

 

[gtrslngrchris]

They don't happen to leave the truck in Auto 4x4 mode do they?

 

[88lance]

Rear shocks are the factory ones. I would think if it is swinging back and forth it would seem like sway bar and other bushings, but that just seems kind of surprising at 100k miles. My 2002 has 223k and is just now starting to feel like it needs swaybar bushings.

I'm wondering if it has something to do with the aftermarket front struts and leveling kit, but I'm not sure why that would only be a problem in the rain. Unless that's the only time it gets that type of uneven stress on each tire on the front from pushing through water, but then you would think it would be similar on humps in the road if that were the case.

My dad was really considering putting the stock struts and front suspension back under it, but having somebody inspect through all the bushings and rods and recheck alignment would probably be the thing to check first.

Sounds like this is a strange issue. I wanted to post in case it was something common that everyone just pointed out right away, but apparently they have something weird going on here. Haha

 

[88lance]

They don't happen to leave the truck in Auto 4x4 mode do they?

I have never seen it in the auto mode, anytime I have got in it it's in 2wd

 

[Doubeleive]

I have never seen it in the auto mode, anytime I have got in it it's in 2wd

is it doing what happens in the youtube video I linked? if so then it's for sure the alignment

 

[88lance]

is it doing what happens in the youtube video I linked? if so then it's for sure the alignment

Not really, there is no movement in the steering wheel from what I understand. Instead of a wobble it seems more like the whole vehicle whipping back and forth, almost like hydroplaning to one side except when it starts to one side it whips back the other way and just gets caught in a sudden dramatic back and forth motion. But according to them, you don't really have to hit a big puddle to make it start hydroplaning to do it, it will just start randomly while there is heavy water on the road

 

[Doubeleive]

Not really, there is no movement in the steering wheel from what I understand. Instead of a wobble it seems more like the whole vehicle whipping back and forth, almost like hydroplaning to one side except when it starts to one side it whips back the other way and just gets caught in a sudden dramatic back and forth motion. But according to them, you don't really have to hit a big puddle to make it start hydroplaning to do it, it will just start randomly while there is heavy water on the road

I wonder if it is because of the electric steering? it might not be sending the feedback to the steering wheel like a regular system.
there is no logical reason for the vehicle to do that unless the alignment is off
otherwise this is a one-off that would be super rare, unknown to me anyways
if it was a abs, traction control, stabiltrac issue normally the system would just cripple the vehicle slowing you down to low speed until it decided all 4 wheels are the same speed and then it would allow you to go again. (it would feel like a ghost is hitting the brakes, or like a rope is pulling the vehicle from the rear)

I would recommend having the alignment done anyway just to rule it out, and mention what it does when they do.
that is a place to start anyway, then if it still does it then it's going to need a more advanced diagnosis. I don't think a leveling kit, tires, shocks would cause this

nobody else that I have ran across has reported any issue's like this by doing a electronic suspension delete, if anything there would be a service suspension message.
and the k2's have been known to limit the overall speed to 80? max if it detects a problem and it does that as a safety precaution because it can't see the data it needs to prevent a accident above a certain speed. this would also be a message that would come up in the dic. or it just would not go above 80 without explanation.

 

[88lance]

I wonder if it is because of the electric steering? it might not be sending the feedback to the steering wheel like a regular system.
there is no logical reason for the vehicle to do that unless the alignment is off
otherwise this is a one-off that would be super rare, unknown to me anyways
if it was a abs, traction control, stabiltrac issue normally the system would just cripple the vehicle slowing you down to low speed until it decided all 4 wheels are the same speed and then it would allow you to go again. (it would feel like a ghost is hitting the brakes, or like a rope is pulling the vehicle from the rear)

I would recommend having the alignment done anyway just to rule it out, and mention what it does when they do.
that is a place to start anyway, then if it still does it then it's going to need a more advanced diagnosis. I don't think a leveling kit, tires, shocks would cause this

nobody else that I have ran across has reported any issue's like this by doing a electronic suspension delete, if anything there would be a service suspension message.
and the k2's have been known to limit the overall speed to 80? max if it detects a problem and it does that as a safety precaution because it can't see the data it needs to prevent a accident above a certain speed. this would also be a message that would come up in the dic. or it just would not go above 80 without explanation.

They are making appointment for an alignment and full inspection of the suspension and steering this week, so maybe that will uncover some answers.
My dad says he drove it and took it down some roads that have uneven pavement, and noticed it does seem to wonder around the road a lot, so I I agree they are probably going to find their problem with this appointment, most likely with alignment or something worn out.

 

[Fless]

Interesting... please continue to update us on continuing issues and/or the solution.