2018 Denali acts weird in rain?

[88lance]

Hello everyone, have a question for my parents about their 2018 Yukon Denali.

This Yukon has stock rear suspension, and the deleted Magneride kit up front, with a small level to raise the nose up a bit.

When driving in rain on wet pavement, the whole thing will suddenly start whipping side to side at random points sometimes. Not just the rear, but the entire thing.

Of course you would think tires, so they had a new set of Michelin tires put on. Finally got some rain today, and didn't take long to find out that wasn't the fix.

Seems like this would have something to do with suspension, since the tires didn't change anything, but I am not sure what it would be.

I wouldn't think a simple level kit would cause it, especially since it has been properly aligned again. Is there something up with the Magneride delete suspension kit that could be doing this? Or is there something completely different we should be looking at?

Anyone ran into this before?

 

[swathdiver]

@PG01 Pete?

Any messages coming up on the DIC while this is going on? How about Traction Control and Stabilitrak lights?

 

[CMoore711]

It only does this in the rain? Never while driving in any dry weather conditions?

What magnetic ride delete kit is installed up front?
What leveling kit is installed up front?

 

[ivin74]

How many miles are on the SUV?
Are the sway bar bushings good?
Are the control arm bushings is good shape?
When was the last time it was aligned? An alignment and suspension inspection will tell you if there are worn out parts.

I would look into these items first.

 

[Doubeleive]

Hello everyone, have a question for my parents about their 2018 Yukon Denali.

This Yukon has stock rear suspension, and the deleted Magneride kit up front, with a small level to raise the nose up a bit.

When driving in rain on wet pavement, the whole thing will suddenly start whipping side to side at random points sometimes. Not just the rear, but the entire thing.

Of course you would think tires, so they had a new set of Michelin tires put on. Finally got some rain today, and didn't take long to find out that wasn't the fix.

Seems like this would have something to do with suspension, since the tires didn't change anything, but I am not sure what it would be.

I wouldn't think a simple level kit would cause it, especially since it has been properly aligned again. Is there something up with the Magneride delete suspension kit that could be doing this? Or is there something completely different we should be looking at?

Anyone ran into this before?

I would take it to a different alignment shop and have it checked (again) there isn't anything else that would cause that but steering/alignment
the only else I could even fathom is if maybe one side of the leveling kit is higher than the other like if it has a different size on the left and a shorter or taller one on right.
but even then that would just make it sit funky.
I would say the alignment is off a smidge

 

[gtrslngrchris]

Can we get a better description than whipping side to side? The way I read that sounds like the vehicle is suddenly losing control but that doesn't match with the rest of what you typed. There's nothing on the vehicle that could act on the suspension in a sudden manner no matter what the magride or lack thereof was doing but the steering could. If it is the conditions or location causing it you would have to see something obvious on the road that caused something like that unless it was steering or grip related. If you are flooring it in the rain and traction control kicks on then you can definitely get some weird behavior but I would suggest that's an issue of user error and it not having supercar level of traction aids to overcome it.

So is the car rocking side to side or swaying or swerving or what? I really can't tell.

 

[Doubeleive]

Can we get a better description than whipping side to side? The way I read that sounds like the vehicle is suddenly losing control but that doesn't match with the rest of what you typed. There's nothing on the vehicle that could act on the suspension in a sudden manner no matter what the magride or lack thereof was doing but the steering could. If it is the conditions or location causing it you would have to see something obvious on the road that caused something like that unless it was steering or grip related. If you are flooring it in the rain and traction control kicks on then you can definitely get some weird behavior but I would suggest that's an issue of user error and it not having supercar level of traction aids to overcome it.

So is the car rocking side to side or swaying or swerving or what? I really can't tell.

whipping side to side sounds like death wobble to me, anything else would result in pretty much crashing/loss of control period

 

[88lance]

Hello everyone, sorry for the late response. It only does it if it is raining and pretty wet, which is what made me think tires at first.
The Yukon has 102,000 miles.

The leveling kit is a 2" kit, and the struts are Arnott.

They mentioned that it doesn't have to be puddles, but it does have to have a lot of water on the road for it to do it.

The body doesn't seem to roll, it just goes side to side in front and back. No traction control lights or any other warnings. They said that they have to let off the gas and reduce speed to make it quit, and then once it quits, it's good to bring back up to speed again.

They mentioned that it is almost the same feeling of hitting a puddle, how it pulls the vehicle to the side, but it is doing it back and forth quickly, and will do it randomly, not just if there is a puddle that was hit.

So it seems to have something to do with handling in heavy rain, which makes it confusing that the tires didn't fix it.

I'm not sure when the last alignment was, or about swaybar and control arm bushings, so the alignment shop may be what needs to happen next.

I was thinking it wouldn't be as likely, at that mileage, but it's definitely worth a check. It makes sense that it sounds like something to do with suspension linkage not being tight.

They asked if it is possible that the lane assistance could be flipping out, but I kind doubt it would react that dramatically

 

[Doubeleive]

sounds just like death wobble, when they take it in for the alignment have them tell the advisor it appears to have death wobble at speed, when wet out. they should be able to inspect for any worn parts and/or adjust it correctly.

that occurs when the alignment is not quite right, it will drive normal up to a certain speed then begin to wobble back-n-forth, sometimes you can accelerate out of it but normally just letting off the gas and slowing down brings you back in control. a wet surface likely triggers it in there case

 

[ivin74]

They mentioned that it doesn't have to be puddles, but it does have to have a lot of water on the road for it to do it.

The body doesn't seem to roll, it just goes side to side in front and back.

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

 

[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.