Hello and I'm new to these threads. I purchased my first Lexus this past December. I noticed a vibration at higher speeds of 60-80 MPH. I assumed it was possibly an unbalanced tire, but it didn't seem to happen all the time. At the 5K mark I brought it back to the dealer for scheduled maintenance. I mentioned the vibration. They had let me use a courtesy RX350 and I noticed how nice the ride was. When time came to pick up my vehicle, they told me they found a tire out of balance, so they took care of it. I noticed immediately on my way home that the problem was still there. As I said before the vibration doesn't happen all the time, but my car never rode as nice as the RX350(not 350h) loaner. Fast forward to the recent 10K scheduled maintenance, I was more of a pain in the ***. I explained how it doesn't happen all the time and never
rode like the loaner. I also gave them videos that I had recorded of my cars vibration at those speeds. The videos were a clear indication that something was off. They said they were unable to test drive at speeds higher than the speed limit, so I would have to drive with a technician. During the test drive the Technician could feel the vibration at 50MPH and only got worse at higher speeds. The vibration can be felt in the seat, accelerator pedal and steering wheel. He assumed a tire balance issue or bad tire. They also gave me a different RX350 loaner, and this vehicle also rode smooth. I hadn't heard anything from the dealer, and I noticed the Lexus app was telling me that the rear windows were down, so the next morning I went to the dealership. They told me that they replaced 2 tires and to take the car for a ride. I was hopeful, but the problem was still there. As I turned around and headed back to the dealer the car rode smooth at higher speeds. This time they let the foreman go for a ride with me and, he concluded that the vibration was still present. I called back after a couple of days, and they said I could pick up the car. The service MGR said they couldn't find anything else wrong, but they had a brand new with 37 miles 2025 RX350h for me to test. It also had a vibration, but worse than my car. I apologize for the long post. I'm just frustrated that I have purchased this vehicle, and I don't have a smooth riding car. Any thoughts or suggestions would be appreciated. Thanks!!

 

Something wrong somewhere. Our 350h is silky smooth at any speed. 12k on the clock.

 

I would take it to another dealer and let them asses it.

 

Did they ROAD FORCE balance all four?? I once had a vibration on a brand new tire and only after road force balance did it get resolved.

 

They have road force the tires 2 times. I would think if it was an out of balance tire that the vibration would be there all the time? This is off and on.

 

In my experience, if you have two out-of round or unbalanced tires on the same axle, they can feel worse if the vibrations are in sync with each other. <--- hope that makes sense to you

Have the wheels been mic'd for 'true'? Even a few thousandths out-of-round can be felt at times.


Has the dealer changed the mounting relationship of the tires to the wheels? That can eliminate vibrations. (The idea is to compensate the road force between the 'high spots' of the wheels & tires. Use a Sharpie to mark the position of the tire valve to see if they changed the position.

 

Tire out of round perhaps. I had that once on a brand new car and it took many visits for the dealer to finally figure it out.

 

Can we assume that the vibration does not occur on the same stretch of highway all the time? That would indicate a pavement induced vibration.

 

My 2008 SC430 with 65000 miles had a shake. My car vibrated at two different speeds. 25-45 and 60-75+. In a word, many things are contributing to the NVH. I replaced the front wheel bearings. That helped just a bit. I replaced the front upper control arms and that also helped a bit. I got new tires and wheels and that helped a little bit as well. But I still got vibrations (steering column, seats, dashboard).
I took the car to a good local shop that deals with a lot of German cars. They test drove it and suggested that the next thing I replace should be the 2 motor mounts and the transmission mount. After paying $1700 to get all 3 mounts replaced at once, the vibrations were greatly reduced to almost nothing. It feels like 95% of the problem is gone now versus 70% before. I also checked the operation of the torque converter at a good local transmission shop. They charged me $60. They told me there is nothing wrong . So I think I will proceed with replacing the sway bar bushing next and the rear upper control arms to get it to 100%.

 

None of those things apply ro a brand new car though.

 

Although my RX is a 350 and not a 350h, I had the same problem with my brand new 2025. There was a noticeable vibration above 70mph regardless of the type of road surface. The faster you went, the worse it got. I took it to the dealership and the service writer said let's put in on the road force balancer. The tires tested fine on road force, but all four were out of balance by 1/4 to 1/2 ounce. I was surprised that small amount of weight could make a difference, but the service writer was confident that would solve it. She was right - it did.

I live in south Florida where they use a lot of coarse aggregate concrete on highways. It's the noisiest, roughest surface you can use and it's annoying as hell. Some pavement types will give you road surface induced micro vibrations at high speeds and there isn't really much you can do about that, or the road noise. Even a Rolls Royce Ghost can't get rid of the noise completely. When I find a freshly paved asphalt section of road the difference is like night and day both from a micro vibration and road noise perspective.