RX350ok

I've been experiencing a vibration in the steering wheel and chassis at approximately 40-45 MPH. Took me months of driving the car to determine something wasn't right. I kept thinking the car was switching back and forth into electric drive, but that wasn't the case. I've taken it in to service 2 times for this issue and there's still an open ticket because the technicians can't seem to replicate it. This issue is intermittent and doesn't seem to matter whether the car is in ICE or electric mode. My dealership has been very good to me through this, but I'm looking for advice of any kind. Thanks!

midcow3

go to a tire store and get balance and 4-wheel alignment.

YMMV,
MidCow3

anoop

Are you able to replicate it?

Are you able to narrow down situations when it happens?

For example, does it happen only when the car/tires are cold?

Could be many things but if they can’t replicate it and if you can’t demonstrate it, unless there’s a TSB they can’t help you.

RX350ok

Yes. I've replicated it many times. I think I've narrowed it down to mostly first start-up. A traveling Lexus tech has also looked at it. But you're right, Lexus will not do much until they replicate the issue. They've checked the alignment and made minor adjustments but it still intermittently exists.
I might try to drive another Nx hybrid to see if it also exhibits this behavior.

TheCDN

My apologies for this being so long!

You're doing all the right things, keep at it! If your dealership is on board with helping you out, trust me, they will figure it out sooner or later. Inherently, vibration is typically caused by moving parts that have a defect in some way. As others have suggested, tires and brakes and alignment are the worst offenders and any technician or master technician working at a Lexus dealership should be able to investigate these areas like the back of their hand! Tire pressures, bad ply in tire, bad alignment, loose or tight suspension components etc all can cause vibrations. You mention at a certain speed and also mostly at cold start-up, these are great observations to tell your dealer tech's. And yes, ask to drive another sample car with same options and drivetrain as yours to see if they exhibit same issue. Here's the thing, most likely something that rotates or is affected by the speed the car is travelling is the root cause. Maybe a bearing somewhere in the drivetrain, a part that has too much play or movement and speed aggravates it, is possibly to blame. And as you drive it more it will probably continue to wear and be more pronounced and easier to notice or replicate to dealer. You obviously have the dealer recording your concerns and they have been trying to diagnose it, so as long as you're well within your warranty period it would be covered when they finally figure out what it is. A good example of this is when a wheel bearing is starting to fail you'll start to get a hum or roar from the floorboard and also in the steering wheel if it's a front wheel bearing and just floorboard if it's a rear. I've experienced this myself a few times over the years and yes it only gets louder as it wears more. This is very easy for a tech to diagnose, simply put it up on the hoist and spin the wheel, they can hear and feel it right away. I'm sure this is one of things they would have checked out already. And no, this doesn't only happen once the car is older, a wheel bearing can fail simply by driving over a big pot hole or smacking a curb while driving in the snow. It won't 'fail' right away but rather damage occurs to the bearing causing a crack or fissure to rolling surface and as it continues to rotate it slowly destroys itself causing the noise and vibration. Any bearing can fail this way, either by assembly, a manufacturing defect or by a blunt force to it.

Just to be clear with some facts you could share to others that may have same or similar issue, it's a '24 350h - what options ie tire size? Mileage when it started and current, time of year or average temperature - when you mention start up - is the outside temperature very cold out?

I had a bad blindspot monitor on my drivers side and my mirror alert light was coming on when there wasn't anything beside me. Trouble was it worked fine as it should, but also alarmed when it shouldn't. 3 visits to dealer over a year, 2 replaced mirror assemblies, a check of alignment for the existing bsm module which is under plastic bumper, AND me taking videos of it happening as proof. Finally they agreed to replace it last month and it looks like problem is solved. All along my communication with dealer and their techs allowed us both to understand where each of us 'was coming from' meaning they had to 'satisfy' their warranty replacement criteria first so that it was going to be covered by Lexus, and Lexus had to cover all the initial inspections and testing too. To inspect the BSM alignment itself was like 4 hours work - which the dealer wanted Lexus to cover.

If you think that taking a video with your phone would help to prove what is happening might help, then do like I did and set your phone up 'ready to record' a video. I know you probably won't see anything but show or say details while videoing like: 'It's Tuesday May 21 2024 at 8 am it's 52 degrees outside and I'm starting my car up for first time today' maybe take a quick shot of your display showing mileage time and outside temperature. If you can hear the vibration your phone's mic should record it too. Keep everything as quiet as possible in car while you're doing this. Talk out when the issue starts maybe say I'm doing 45 now and can hear it. Possibly road surface might play into it too, my BSM issue was affected by road surface, bad rough roads that made the car hum would cause the fault to happen and I could prove that certain rough roads had the highest repeatability for my issue. I think the vibration was shaking the module and an internal fault was root cause.

With my experience the tech's let me know that sharing the time and date stamp and gps coordinates (as you can find in 'information' section for a photo or video done on an IPhone) they can look at stored data in the car to see what was happening at that time. Apparently all the different safety tech and electronics store info for retrieval by the technicians to look at which may shed some light on something.

Look at it this way, it most likely won't get better on it's own but will get worst as things continue to wear out if that's any consolation for you. And this should make it easier for the dealer to diagnose.

Droid13

Have you rotated your tires since initially discovering the issue. It would be interesting to see if doing so changes the nature of the vibration and if so, hint at next steps.

anoop

I read somewhere Lexus had a problem with some tires where they’d have flat spots when cold but be fine once they warmed up. If you can start to reproduce it consistently then you could leave it overnight and have tech drive it when cold. However as temperatures warm up you might find the problem goes away.

RX350ok

I've been experiencing this with my car since new (December '23). Also, you have 12 months or 12k miles for Lexus to pay for alignment/ tire balancing. I'm currently at 4k miles. I'm taking the car back to dealership for 3rd time next week for this issue. Sadly, other than Lexus checking the alignment, I don't think they've checked tire balance.

RX350ok

I think I've narrowed it down to cold start and 41-44 Mph. But not exclusively.

RX350ok

I have a Premium model with the 18" wheels/run-flats. I started experiencing this early on with car and was probably present from the beginning. At first, I wasn't sure what was happening because it's a hybrid and I wasn't used to how the drivetrain operated. Once I set my preferences in system and had the "EV" light set to come on during EV operation, I started to connect the dots. I think it's happening more often during cold start, but not exclusively.
Thank you for your video advice. I've tried a video and this vibration is only felt while driving, not heard or seen.

RX350ok

This is interesting and would definitely explain why it's more apparent at cold start.

RX350ok

Took my NX back to dealership (3rd time) this week for the vibration issue. They balanced the tires but it's made no difference, the vibration is still there. I haven't called to reschedule. They've never been able to replicate the issue on their short test drives. I'm going to try to drive another 350h with '18 wheels to see if I can replicate it in another vehicle. Any other advice would be appreciated. Thank you!

kukudm

If your dealership is willing to help you, ask them if they can swap the tires from another NX on the lot. Then you drive your car to see if the vibration is still there.

midcow3

Wow, If your dealership will do these then they are excellent !

kukudm

Yea, I got a friend in service. I even asked for a custom alignment once. Anyways, swapping a set of wheels isn't very hard, if the dealership is willing to help to get to the bottom of it, this is a very simple thing to try.