Grumpa72

Well, I certainly can not tell you how your car feels or sounds merely by your description. However, common sense and a bit of investigation will tell that if the car only shakes and makes the sound with the wind down, then it would certainly seem to be a harmonic vibration as I described. Again, common sense would dictate that the car would shake with the windows up or down! Since the windows can have absolutely no effect on the tire vibration or tread separation, don't you think it is odd that the car only does this with the windows down. How can the car have such good sound proofing that you don't hear a thing until the windows are down?

I will wait for your report, but based on your observations, as well as the history of this type of report, I would bet money I know what the outcome will be.

Please keep us posted.

Gary

KeysRx300

You will find it is the wind. I had the same thing on my RX300. A helicopter type of sound. Very loud at highway speeds. With a nice vibration.

Lower more than one widow and it will go away. But with the windows down. The seat belts that are not being used will start flapping.

jednav

Ok, was able to get my RX checked today. The VERDICT: tire thread separation on the rear driver side.

The mild vibration was the strong indicator. Lobbied for replacement of all four tires but settled to new rear tires.

Vibration is gone, acceleration smooth, swirling wind sound gone (just because rear windows are up )

CK6Speed

iTrader: (1)

I guess you proved us all wrong. Glad you got it fixed.

andreys

try to have better description next time. Your original post was somewhat misleading

mandyfig

Michelins...tire tread separation? Wow! This is not a good sign. What else did they say about the tires? Was it visible? Did you see the tires? Anyway good for you they replaced both rears.

salimshah

Glad the problem was isolated and fixed.

As an afterthought one of the things that could have been tried was to move the rear wheels to the front and see if the source moved.

Salim

jednav

Tread separation is not visible to the naked eyes. Worse case would be a split in the rubber surface but you will not reach that point since your vehicle will no longer be drivable.

If it were the front tires, the first sign will be vibration of the steering wheel.

Hope this info helps.

kingofire

So if it is not visible to the naked eye, how do they diagnose "tread separation" Sorry am a novice at this as I have never heard of this before.

tgdaman

Please allow me to politely disagree. My analysis of the problem was not proved wrong.

The G Man

If it is tread separation, shouldnt the RX shake with the window roll up too?

mandyfig

I would imagine your are right GMan! Weird. Leaves me to believe there could have been "other" issues not divulged? Speculation. But with or without windows open a tire issue is a tire issue.

Grumpa72

And shouldn't have heard it with the windows up? I believe that is why some have questioned your initial description and gave you a diagnosis based on your observations. Too bad your dealer didn't give you a new set of tires.

Don't get me wrong, I am very happy that you found the problem BEFORE tread separation and potential loss of control. When I inherited my mother-in-laws 19 year old Mercedes diesel I drove it from San Antonio to Pittsburgh. I started feeling a weird vibration and sound (with the windows up, ac on, and 70 mph ). One minute or so later the right rear tire went flat due to inner belt separation followed by tread separation. In my haste to return the car I had prepped it for the trip - new oil, filters, all other fluids checked but I failed to notice the sidewall cracking when I put air in the tires.

jednav

The vibration must have been there but was unnoticeable yet. It became pronounced with the windows rolled down and the wind beating on it.

I did not tell the dealer of my suspicions (thread or axle), and was glad it just turned out to be the tires.

How did they diagnose the problem? Lexus dealerships do know a little about Lexus vehicles !!