lexuslover

has anyone had strange noise from underneath the car around 75mph+? it's coming from underneath the driver side; sounds like its near the front driver wheel well.

the strange this is there is no noise whatsoever from 0-75mph. once you reach 75+, the noise starts. it's not a constant flapping noise (like a flag blowing in the wind), but more like an intermittent nuisance. it basically sounds like you are running over small rocks or debris and the debris rolls up into the wheel well and/or smacks the undercarriage. the noises occur within a few seconds of each other, and will not subside until mph is reduced below 75. (i am not driving on newly paved roads; this is on a regular freeway like I-5 on dry surface, no debris)

i've had the dealer check in the past, but nothing was ever found. it's not too much of a bother since i don't regularly drive above 75, but occasionally on long trips to LA or NorCal it can really start to bug...

p.s. i'm at 52,000 miles. at 49,500 the dealer did over $3k in warranty related repairs and the car is running great. very quiet and enjoyable... that is until i reach 75mph

Lil4X

If you've already tried wiggling everything in the area to see 1. if you haven't picked up a plastic bag or something that is stuck in the undercarriage, or 2. you have something loose that starts flapping at speed ( I'm sure the dealer did this ), you might try this:

It may sound a little silly, but on a good windy day, see if there is a difference in the speed at which this noise occurs when driving directly into the wind versus driving with the wind. If there is a steady 20mph wind - and the problem is really related to airflow over the vehicle - there should be roughly a 20mph difference in the speeds at which the noise is first heard. If there is no appreciable difference, maybe the problem is mechanical in nature and not a loose fender liner, rubber, or vinyl fairing. At least it would narrow down the sources.

Tammy

Insure the tire rotation and balance is correct. Mine did this type of thing until I had the stick-on flat wheel weights replaced with the wheel weights that attached to the inner and outer wheel edge. The out of balance condiction caused the plastic inner fender to vibrate.

Lexus sells the wheel weights that fit the Lexus wheels. I needed chrome weights on the outside.

Orzel

iTrader: (1)

May or may not be the same thing, but on a recent trip, I hit a piece of semi tire (truck kicked it up) and it took out the left air splitter (little tab that hangs down in front of the front tires). As we continued on our road trip, each time I got over about 75 I started to hear this flapping like noise. In heavy headwinds the noise came on at a lot lower speed. Turns out that the air splitter has something to do with keeping the inner fender liner from flexing (oil-canning). Now I have a nice hole rubbed in the liner from the front tire impacting it at speeds. Will have it all fixed when I have my 15k mile service done.

lexuslover

hmmm, i will definitely check out that little tab thing. i don't think it's missing, but it sounds like it has a purpose beyond just being there... who woulda guessed?

Orzel, are you saying that your tab thing is completely gone? what is the tire hitting now that is causing it to leave a hole in your liner?

Orzel

iTrader: (1)

Oh, it’s gone alright, ripped right out of it’s mounting in the lower front of the inner fender liner. With it gone, the fender liner tends to bow toward the tire at high speeds, and "oil can" (flex).

I now have a nice oval hole worn into the liner at between 10:00 and 11:00 (when standing facing the left front tire). First it was an irregular flapping noise, then when we hit some stiff headwinds it would “grind” a bit, but only now and then. As the winds increased (and so did my speeds) I managed to wear away portions of the liner. Once we figured out what it was (and I called Lexus – who said no real danger) we lived with it for the rest of our trip. It’s annoying, it’s going to cost me a new inner fender liner and the installation of same (not a task I can do because of physical limitations), and I’ll have to take a day off to go to my dealer, which is almost 100 miles (one way) South of us.

Anyway, check and see if the air splitter tab that hangs down, or should hang down, in front of your front tires is still there, or loose.

Hope that helps.

blue_rx330

I had that noise -- but on my RX - it came from the driver's side rear wheel well. You can check to be sure by asking somebody to ride in the back seat and listen when you hit 75. For a person sitting in the back seat -- the sound seemed to be coming from the gas-tank/rear cargo area...but if you put your ear towards the glass - the sound seemed to shift to the front.

Reach up into the rear wheel well of any '04 Rx330 (I checked about 10 of them on the lot once I discovered it)...you will find that the plastic liner is indeed loose and unattached at the top by design from the factory. I solved my problem by buying $3 worth of self adhesive pipe-insultating foam from Home Depot. I cut a 14" piece and had it wrapped around the top/un-attached liner. Bingo -- problem solved.

If its the same problem -- $3 fixes it for good. Mine has been in place for almosts 3 years.

lexuslover

wow, that is amazing. can i ask a HUGE favor - do you have any pics of that area? i just want to make sure i am looking at the right thing.

i checked earlier and my front tab thing is still there, so i ruled that part out. but now i am thinking yours sounds pretty dead on in terms of the noise. i've never asked anyone in the back to listen, but i do think sometimes the noise is further back than the driver wheel well.

and sorry for the lack of DIY knowledge, but what exactly is the foam? if i go to Home Depot and tell them i need pipe insulating foam, is that enough? or do you have a specific recommendation on a certain product?

i can't wait to tackle this problem this weekend... thanks for your help!

blue_rx330

This picture is looking up into the driver's side side rear wheel well. The black plastic liner is the problem -- its completely unattached at the top -- so it just flaps around over bumps and in high winds. It also transmits gravel and stone noises into the passenger cabin.

Here's what I did, and so far the fix has lasted the life of the car...

1) wash the plastic liner
2) clean it with rubbing alcohol at the top
3) wrap the foam tube around the liner at the top (I used 2 layers)

And I found the tube insulation at my local Home Depot..this isn't exactly what I used -- but it looks similar...you don't need much...so buy the shortest tube they have.

Link to Sample Tube Insulating Product

And choose the SOFT-RUBBER type of insulating tube...not the rigid style. (We're trying to silence noises and vibrations after-all)...

That's it -- no tools - no need to jack up the car. I hope this foam-trick works for you....

tfischer

I think I speak for all of us RX owners here when I say thank you very much.

That pic and the link are about as helpful and informative an answer as you can get, unless you want to come over to my place an install it yourself.

Surely among the most helpful posts of the year.

lexuslover

blue, you are too much! thanks so much for your help. i am going to take a crack at it this weekend once i get all the foam. i will report back to let you all know how it goes.

and yes, you get 5 gold stars for your post! THANK YOU THANK YOU THANK YOU!

Orzel

iTrader: (1)

Will be interested to know if that takes care of the noise. I'll have to wait till I get my fenderliner fixed and then see if I'm getting the same from the back.

lexuslover

ok, here's the scoop:

i drove around after doing the fix and the flapping was still there. i had my husband sit in back while we were going 75-80mph and he didn't think it was coming from the rear. then later he drove home and agreed that it was directly under the driver seat. so i got home and took a look under the car beneath the driver area and there really aren't a lot of moving parts. mostly metal frame and then a plastic pan that covers a large area underneath the car. the shape of the plastic is such that it faces against wind flowing underneath, and like the rear fender lining, it is not attached at the top or sides.

luckily i bought an 8ft piece of foam at Home Depot since that was all they had. i used the excess to cut a few more pieces and stick it to the edge of this pan, and then drove again this morning. the noise is gone! i think i may hear a few things here and there from underneath, so i am probably going to add another strip of foam where i put a yellow line in the picture below.

hopefully this is the solution. i will continue to take note and see if the noise comes back, but for now the noise is non existent!! i would have never thought of this had blue_rx330 not shown us the fender liner design. (thanks again blue!) it's hard to believe that something so minor can result in so much noise, but i guess that is a design flaw. hopefully they addressed that on the new 350's, because it seems strange to leave plastic like that to get bumped around by high winds or speed.

sharpener

i think i have a similiar problem too, but mine occured @ abt 55mph...
its getting on my nerves too
here are some other suggestion i posted earlier
https://www.clublexus.com/forums/sho...d.php?t=205110

blue_rx330

Congrats! And believe me -- I definately know what its like to have the source of an annoying noise located. It's a good feeling...Savor the victory!