I just bought a 04 RX330 with 73,000 miles on it. I noticed this rattling noise that was DRIVING ME CRAZY!!!! It would only happen when I went 35 or over.I took my friend for a ride to help me pin down the noise,we were both convinced it was coming from the drivers side dash somewhere.
I played around with the dash a little but the noise was still there so I started looking around the vehicle,under the hood around the tires etc etc. I was looking under the vehicle and there is a plastic shroud covering the gas tank and it seems the design leaves a piece kind of just hanging there. I looked at the area above the piece and it was apparently vibrating on the underside of the vehicle. I temporarily stuffed a rag in there to bring it down lower from the underside and took it for a ride...NO MORE NOISE!!!!

I read about all the unresolved dash rattle issues and thought this might help someone.

 

I have a 2007 RX350 with a similar rattling noise, but mine sometimes sounds like it is under the front hood -- almost like a hose is knocking against the underside of the hood -- and sometimes it sounds like it might be the luggage rack. Has been driving me nuts....I will check into your solution. Only happens at higher speeds.

Thanks!

 

There's a long thread about this issue. The noise is reported coming from all over the car but it always seems to be that plastic part. An inexpensive solution reported is using 3M two sided tape to reseal it.

 

Ours only has the dash "itching" in cold weather, under say 45 degrees. When it warms up, it goes away. I solved a similar problem on my motorcycle saddlebag using Velcro. Unfortunately, you would have to remove the dash to do this. Wherever the dash contact points are, apply the soft half of a piece of velcro (not the spiney helf). This will act like a cushion and will prevent the plastic on plastic "itching" sound.

 

Can someone point me in the direction of this "long thread" about rattles?

We just picked up an 06 350 yesterday, and there is a rattle coming from in the cabin that is driving me nuts !

 

Search and ye shall find...

https://www.clublexus.com/forums/rx-...of-driver.html

 

Just as a side note for consideration, when it comes to the gas tank shield, small stones can and will get kicked up and into the shields and rattle like crazy... Took mind down this morning and found a hand full of tar covered stones under the shielding. Here in Texas (and other places I am sure) they love to seal coat the roads with tar and stone. This definitely lends its self to accumulating stray stones all over the vehicle. It also really sucks when they get tracked into the interior on a 100+ degree day... ERG!

 

My 2004 RX330 with 142K miles recently started making a flapping noise at 30 plus mph. The noise was more pronounced and more frequent at higher speeds. From the drivers seat it sounded as if were coming from the bottom of the door or front left wheel well...it was annoying! Thanks to this forum..problem solved..thanks ALL! It was the gas tank cover! Easy to get to, under the car, about a foot in front of the "seam" where the drivers door and left passenger door meet. About a foot or so under the car. I read about the "dealer's fix" (cutting a piece off) but decided instead just to glue it back. Used a glue for plastics and metals and braced the end until it dried! Again thanks ALL!

 

I had the same annoying problem that was driving me nuts. It's crazy how a shield on the middle left of the car and emit a noise that sounds as if it was coming from the driver's side roof area. I just had my tech cut the flap of plastic off just enough to keep it from touching the floor pan.

 

I have a dam rattle that i am trying to solve ..coming from the rear seats or rear door/floor ... driving with the rear seats down its still there.... getting close now lol.... banging my hand on the rear plastics gives plenty noise, thought it was the tool kit lid hinge, sorted that out, we have the worst roads here in California .... checked the plastics underneath .....2009 rx350

 

A friend had a similar issue and finally an ex Lexus Tech who owns a shop now, cut a plastic spoiler in the bottom. Wish I had looked at it. But will do one day and will take a pic. Seems like a typical issue with the old Rx's. Luckily mine has not done it, knock on wood.

 

Found that plastic underneath in front of the gas tank, no noise from there,...it has foam padding where the piece touches the body, seems all the plastic on the rear smacking it makes some noise, even tapping on the black plastic hood at top of rear door makes rattle, not giving up yet lol ....could it be the linkage from the power motor rear door...

 

Dam the roof rack, it has rattle when i smack it, put an elastic strap to pull the cross bars tight, cardboard inside the compartments and under the two hinges, keep pressure under lids... road test no noise, will run for a while, think i will pull the cross bars later, never use the roof rack anyway..
Forgot about the plastic cover under the spare tire thats a rattler as well wedged some garden hose between tire and plastic
Update ... after test run out no big rattles only noise is from rear seat think its passenger side have to run with seat folded, think my problem was roof rack and spare tire plastic cover underneath
Another thing i found pull the lids in the rear now look at the bins ... they are loose and moving .. check the plastic nut in left and right small bin, then pull them two plastic things holding center bin in place, sling them and get the push pin type, now its good and tight.
No more rattles.......