shoebopper

Just wondering...I have a clacking sound coming from somewhere in the interior, possibly under the driver seat or in that neighborhood. I can be going down the road, smooth as silk, and this thing is clacking in response to road vibrations (my guess). I have read other threads where a similar noise was caused by a backseat (tried the fold and unfold to no avail). I don't think it is the issue with the cover in the rear. The noise just sounds as if it is coming from under the seat. It could be transmitted from elsewhere.

I know there is a vent under there, and the clacking sounds like two pieces of hard plastic vibrating off each other. But the vent doesn't seem to be the source.

Any ideas/help would be appreciated!

HimSelf

have you tried this post?

https://www.clublexus.com/forums/rx-...ml#post5858445

vg1134

check under your car (driver side) and see if the gas tank cover edge has a foam tape at the end. In my car the foam had fell of and when you were driving it would rattle-making it sound like it was inside-but it was outside . I have a previous post on this...

shoebopper

I'll check under the car about the fuel tank cover. Makes sense...the rattle being related to movement and independent of what's happening inside. I really don't think it's a dash rattle caused by a bad servo motor, but I won't eliminate the possibility.

If it's the fuel tank cover, did you just use tape insulation?

Thanks for the ideas.

PatAgent

I had the same problem, and I found that it wasn't the road condition that caused the noise, it was air speed.

Usually, the sound would occur at around 60-65 mph, but one day, the wind was really blowing while I was traveling at only 35 mph, and I heard the "clacking." I looked under the RX and found a guard that could rattle if exposed to higher wind/air speeds. I put some duct tape on the guard to see if that was the problem, and BINGO!

When I took the RX into the dealer for its next service, I told them that I fixed their rattle with some tape. They volunteered to fix the guard for free with a new design (one that doesn't rattle).

Good luck with the sound/noise hunting! It can be a real adventure!

shoebopper

Do you remember which guard it was? I am going to try and find the time this weekend to crawl under and check everything out. I reached under around the fuel tank a couple of nights ago and I can see the opssibility of it being the shields on the fuel tank, as they are kind of loose and bouncy.

Anything to stop the noise.

brendam24

I had the same problem when driving on the highway i kept hearing a noise and thought it was under my driver seat or passenger driver seat and nothing...i took it to lexus and they told me the foam that goes on the gas plate to protect it was worn out so it had to be replaced...the foam it self was only about $5 i think...i was going to have it replaced by my husband but when i picked up my car they went ahead and repaired it...no more claking noise while on the highway...

PatAgent

Shoebopper, the foam is the solution (brendam24 has the right fix)!

As for the location of the guard, it is on the driver's side directly under the car where the driver sits. It is approximately one foot inboard from the outside of the car. If on your knees, you can reach it with your hand and flex it to touch the underside of the car (thus, somewhat replicating the noise).

Good luck!

shoebopper

I think I know which guard/shield you are talking about. Does anybody know what kind of foam/ foam tape/etc. to use? I can fix that myself.

Seems as though I should be able to get something at the hardware store...maybe sticky back no more than an inch wide?

PatAgent

Any type of 3M foam tape (single-sided) would work well. Make sure it is about 1/4" thick (or more), 1/2" wide, and about 4" long. This tape will be attached to the guard.

Just be certain to clean the guard surface well where you are attaching the tape (use mild soap and water, then wipe dry--if possible, use a small amount of isopropyl alcohol to do a final clean on the plastic surface).

Then, enjoy the peace and quiet!

shoebopper

Well, I know it's been a while, but here's what happened.

A couple of weeks ago, I was performing some brake work (another thread) and looked at this gas tank shield. I pulled it down (four nuts hold it in place), and found a piece of the original foam almost gone from the edge of it. The remaining foam pieces seemed OK. I replaced the foam, reinstalled and thought that would fix it.

As it turns out, it didn't. Immediately, the noise started back up when I took the car out for a spin after the brake job.

Fast forward to this week. I had to remove the left rear tire to have a leaking valve stem fixed. I decided to take another look at the shield. What I found was that there was a portion of the shield that juts out in front of the rest of it by a foot or so, and has no support. I tapped on it, noticed where it hit the body and saw a wear mark. So, I grabbed a piece of the foam tape and stuck it on. So far, no more noise!

What I do remember is that this part of the shield did not have any foam on it and had no indication of ever having foam on it...so, who knows why it suddenly decided to do this? If there is a replacement part for this that was redesigned, I would be interested in getting the part number and talking to the dealer about it. It only takes a couple of minutes to replace it, even without jacking up the vehicle.

I like the peace and quiet...now, if that darn dash rattle and tonneau cover rattle could be fixed...

numbafree

I just wanted to update this thread. I bought a used RX 2005 in Feb, and this annoying tapping sound under the driver's seat at freeway speeds literally was driving me insane.

where is this fuel tank shield? driver's side rear wheel in front of the rear wheel. It's not quite in the middle of the car. and it's just one shield, all by itself. You want to put foam tape (like you would for the bottom of a door, like a weather strip) on the edge pointing towards the front bumper. I wasn't looking far back enough, I thought the noise was coming from the under belly pans, protecting the transfer case. but the fuel tank shield is further back.

There is a TSB for it, but by now all 04-09s are out of warranty by time.

part number if you want to punt and easy fix: 776410E010

May the force be with you.

tawm

Belated thanks for this thread. My local CT dealer wants $520 to replace the gas tank cover, instead of this easy fix. They are really driving me to find an independent Toyota/Lexus mechanic. Anyone know one in Fairfield County, CT?

myw

may not be fully related, but also be sure to check the wheel bearings if there is excessive road/tire noise.

crz95

Check the rear hatch. Might not be your case but I've always had issues with it that drive me crazy.
I too felt like the noise was coming from under the driver seat but it actually turned out to be the hatch creaking over imperfections on the road.
Tried to grease it up, no luck. WiIll check what to do on my next service.

Have someone drive the car while you sit in the back seat inspecting the source of the noise.