Dashboard/windshield Area Rattle.... Any Fix?

[KCTalker]

Hey all:

I've got a '95 SC400 (82k, nice shape) for about four months now, and have been able to eradicate just about all of the interior rattles it had--until now.

The temperature's just dropped (here in So. Calif), and now there's this annoying rattle that seems to come from the top of the dashboard, all along the bottom edge of the windshield (where it meets the top of the dash, in the neighborhood of the defroster vents).

I did a little searching, and it seems there's a Lexus Technical Service Information Bulletin (TSIB) about this for the RX--which would probably be helpful--but I couldn't locate the bulletin itself.

Regardless, I'd *love* to fix this, and I'm guessing it's not uncommon, either.

Any tips? Help? A location of that TSIB? I can't even find out (via web-searching) how to remove the complete dashboard anyway (the whole, vinyl top portion that rides atop all the instruments, glove box, etc.).

Any help would be greatly appreciated. I've got this nagging feeling that if I can get to the rub-points, some basic spongy weatherstripping will silence the problem, as it has for 99% of all the other interior noises I've found on this thing.

Thanks in advance, fellow Lexites!

[obsidianr]

Hey all:

I've got a '95 SC400 (82k, nice shape) for about four months now, and have been able to eradicate just about all of the interior rattles it had--until now.

The temperature's just dropped (here in So. Calif), and now there's this annoying rattle that seems to come from the top of the dashboard, all along the bottom edge of the windshield (where it meets the top of the dash, in the neighborhood of the defroster vents).

I did a little searching, and it seems there's a Lexus Technical Service Information Bulletin (TSIB) about this for the RX--which would probably be helpful--but I couldn't locate the bulletin itself.

Regardless, I'd *love* to fix this, and I'm guessing it's not uncommon, either.

Any tips? Help? A location of that TSIB? I can't even find out (via web-searching) how to remove the complete dashboard anyway (the whole, vinyl top portion that rides atop all the instruments, glove box, etc.).

Any help would be greatly appreciated. I've got this nagging feeling that if I can get to the rub-points, some basic spongy weatherstripping will silence the problem, as it has for 99% of all the other interior noises I've found on this thing.

Thanks in advance, fellow Lexites!

←

Unfortunately I don't have an answer to your question. But I was wondering how you went about eliminating all of your other rattles? I have several of my own that I would like to take care of. Thanks!

[artseattle]

KCTALKER, sorry no anwers from me. I have the same problem with my 1998 SC400. I was hoping you found a solution. With my problem, the rattle sounds like two pieces of plastic tapping on each other. It sounds like it is coming from somewhere down in the defroster vent. I rolled towels and covered the vents and the sound was muted.

Just checking to see if you found anything?

Art in Seattle

[bent-one]

KCTALKER, sorry no anwers from me.  I have the same problem with my 1998 SC400.  I was hoping you found a solution.  With my problem, the rattle sounds like two pieces of plastic tapping on each other.  It sounds like it is coming from somewhere down in the defroster vent.  I rolled towels and covered the vents and the sound was muted.

Just checking to see if you found anything?

Art in Seattle

←

i've had the same problem with my mercedes for 2 years now, only during cold months. i've tried just about everything to eradicate this rattle but i think i have it narrowed down. my best guess is that when it's cold, the sealant for the windshield contracts, causing it to rattle where it meets the dash. i'm not 100% about this but it seems like the only option in my case.

as far as my sc goes, no rattle there yet, but i probably would'nt hear it over the rattle coming from my sunroof.

[KCTalker]

KCTALKER, sorry no anwers from me.  I have the same problem with my 1998 SC400.  I was hoping you found a solution.  With my problem, the rattle sounds like two pieces of plastic tapping on each other.  It sounds like it is coming from somewhere down in the defroster vent.  I rolled towels and covered the vents and the sound was muted.

Just checking to see if you found anything?

Art in Seattle

←

Hey Art,

I took a check-ride with a Lexus diagnostic technician at a local dealer, and we narrowed it down to either the cowling covers (black plastic shields outside the windshield, under the wiper arms; there's a tech bulletin for a smilar ticking-noise fix on RAV 4's), or the dash itself.

To isolate the problem, you need to remove the wiper arms and the two (L &R) cowl covers, then drive the car. If the problem goes away, then it's, clearly, the cowling covers and not the dash. If that's the case, insulate the underside of the cowl covers and put 'em back, and you're done. (That's the RAV 4 fix, too.)

After leaving my car with the dealership (where, presumably, they performed the test described above), they said that the problem is the dash itself: the pins that hold it in place need insulating. Sounds simple, but I've downloaded the SC400 shop manual from Lexus--and the dashboard removal requires *eleven pages* of the manual!! It is a *bear* to get to those pins. So I wasn't shocked when the dealer estimated eight hours (about $760) for the fix.

However, there's a quick/cheap/easy fix you can try, which I also learned from a Lexus dealer. Get a can of dry silicone lubricant, and spray a ton of it into the crack between the dash and the windshield. Keep a clean rag on hand to wipe up the inevitable overspray. It quiets the noise a bit--not completely--and only costs about three bucks.

[KCTalker]

Unfortunately I don't have an answer to your question. But I was wondering how you went about eliminating all of your other rattles? I have several of my own that I would like to take care of. Thanks!

←

Hey, Obsidianr,

I found the magic words to eliminating rattles from numerous Lexus tech bulletins which I found on the web. And those words are "foam" and "felt." That's exactly what Lexus recommends!

For any given rattle, first search the web (specifically, sites like this one) for a Lexus tech bulletin ("TSIB") for your exact rattle, 'cause if you can find it, it's your holy grail. And that's because the hard part about eliminating rattles is not fixing them, but rather isolating them.

I have a remarkably tolerant wife, and many times, I'll ask her to drive my SC on a nearby bumpy road, while I listen, and press against trim panels and what-not, to find the source of a rattle (without crashing!).

A rattle is simply caused by the noise of two hard surfaces colliding when the car hits a bump. So to eliminate it, you need to introduce something soft--such as sponge foam or felt--to absorb the impact at the mating surface. I found an annoying rattle (as if any *aren't* annoying!) coming from inside the seat-back of the driver's seat. After popping off the back cover, I found a hard plastic connector dangling suspiciously close to a metal spring bracket. So I wrapped the connector in an old piece of cloth--and the rattle was gone.

I found another rattle *under* the driver's seat: turned out that the seat motor computer (i.e., a metal box) was a little loose, and was hitting the metal seat frame. It was basically pretty tight, so I ripped chunks off an old sponge and wedged them between the box and the frame--and the rattle vanished and never came back.

Another nice anti-rattle tool is self-adhesive sponge-foam weatherstripping, which is dirt-cheap at Pep Boys. I used that to eliminate a buzz from the moonroof: turns out that the wind-deflector was buzzing against the roof while retracted (moonroof closed). The giveaway clue here was that there were *already* little pieces of Lexus foam around the thing, so you know it was a built-in rattle fix! But over the years, any sponge shrinks, or felt compresses, and its efficacy is lost. I've also used foam weatherstripping to eliminate a console rattle above the climate control, and additional sponge to eliminate a rear-deck rattle. So now, with the exception of my admittedly-minor windshield ticking noise, the car is all but silent.

So I really love fixing rattles, when I can, because it costs nothing, requires minimal technical prowess, and ends up making the car really feel like new.

Best of luck with your SC!

[rx33066]

I had a rattle where the dash meets the window. I called the local dealership and they suggested a cheap solution. They told me to buy a 11/32 section of vacuum hose and thread that between the dash and window to absorb the rattle. So far its worked pretty well. My out of pocket expense less than $6.

Now if I could get rid of the rattles that appear to be coming from the two front air vents. Any ideas?

The local dealership quoted me $800-1000 to tear apart the dash so i hope this cheap fix works when the cold weather sets in this fall.