I know this has been talked about in the past. I tried a search,but didnt get too much information. This morning on the highway,going around 70-75 I hear what sounded like the plastic cover underneath the vehicle might be loose. So when I got to work, I took a quick glance under the car, but didnt see anything loose. When I get home, I`ll crawl under to make sure nothing is loose. I really love the way things like this just pop up overnight! totally unprovoked? It was just fine yesterday? Oh well,normal wear/tear I guess. Any other suggestions re; this?

Thanks,
Ryan

 

You may have caught litter (plastic bags are notorious) and when you slowed down/stopped it may have fallen off.

Test on your way back ... I am not suggesting that you drive above the posted speed limit.

Salim

 

Good chance the foam came off the front edge of that shield. Drove me nuts for weeks. I need to replace my foam now that I think about it.

 

I have a similar sound... Sounds like it is coming from the rear... I am wondering if the plastic cover on the spare tire is flapping in the breeze... Will try taking it off and shoving something between the underbody and the gas tank shield under the drivers side. We will see if that works... Only really bothers me when the radio is off and the roads are smooth... Oh, wait neither of those conditions are normal so I will just turn the radio on/up... ;0). I think I will take shoebopper's advice and do those things now while I am thinking about it...

 

It is the plastic shield under the tranny. Did you recently have an oil change? If so, the idiots put it back on the wrong way.

 

Be sure to also check your trim pieces as necessary.

 

Okay,last night when I got home,I crawled under their and everything seems to be in order? So this morning while on RT 33 N I did around the same speed.....and wa la, no noise?? I cant figure this stuff out some times.

 

What foam are you referring too?

 

Thanks Salim, I usually dont go more than that. Unless I have to pass one of the big rigger`s that like to speed up while your passing them. That seems to happen way to often anymore, along with the dumb asses that like to pull out in front of you, when their is no body behind you! Rant over now...

 

I had similar sound (tapping sound). There is a (relatively) small plastic cover at the left (driver) side approx. in the middle of the RX (at the bottom). The "beak" of it (facing forward) is not connected to the body (just touches it) and may flap, especially if it was bent (let say in winter, snow can get under it and bend it down).
I ended up cutting the front part of this "beak" an sound disappeared.

 

I saw that very same piece your describing here. And I thought,well if thats what`s making the noise, there isnt a whole lot I can do about it.

 

I cut it off (about 7-10 centimetres) until it was not touching the bottom. Sound disappears. Well, you can replace the whole cover.

 

The foam is supposed to be on the front edge of that shield that just flaps around. I am guessing that if you removed the shield, you would see an outline of the foam placement. Judging by what I have seen underthere, the foam was a fairly dense material, and deadened the sound of the impact with the underside of the vehicle. I found some generic automotive weather strip type stuff (not quite as dense - Autozone), self-adhesive, and for a roll that cost around $5 I can fix my tapping sound for a long time, as it only took a 4" - 6" piece. I think it calls for you to use some denatured alcohol to clean the area...but do what you got to do to get the tape on and silence returned (onlong with sanity).

FWIT - I understand that there is a redesigned piece available from Lexus that solves this...probably they cut off the front edge as suggested above!

 

Yeah, I also thought about this solution, but my car was anti-rust sprayed on the bottom and the stuff is oily - no good for adhesive. It's all over the bottom and the plastic cover has some on it.