DJC

Sorry about the delay in getting back to you all...been traveling and working some long hours. Anyway, looked under my car this evening and all the holes described by SeattleGS400 above are pluged on my car except for one of the dime sized along the inner front passenger frame rail. Looks like it may have fallen out. I will stop at the local dealer (Park Place in Plano, TX) to see if they have one.

SeattleGS400

iTrader: (1)

DJC:

Hey thanks for looking at those holes for me and confirming if the holes are plugged up or not. I really appreciate it greatly. I'll head over to the dealer and get some plugs next week to seal up the holes.

Also, 3dog, I really appreciate you taking some time out of your day to look on your car. Looks like you, too, have some plugs missing. Do you have any wind noise that permeates the car at freeway speeds (like I do)? I wonder if the '99 GS400 have different plugs than the newer GS430? Highly unlikely, but something to consider. . . maybe other GS4 owners can also confirm?

In any event, I'll look to get the rubber plugs for the holes. Will report back on the results of plugging those 4 holes up. Thanks for the help guys.

doug_999

SeattleGS400,
Sorry for the delay - my 03 GS430 has the front ones plugged but both rears are not plugged.

Doug

SeattleGS400

iTrader: (1)

Doug:

Thanks for your help as well. From the collaborative information:

1. It looks like those front underbody holes definitely need to be plugged up. The passenger side front hole is esp. important considering the shape (it's angled perfectly for wind and road noise to blow directly into, resulting in apparently loud passenger cabin at freeway speeds masquerading as a bad window seal). The driver's side has a similar effect but as the hole is on a flatter plane, less noise gets in from there--but is still noise, nontheless.

2. The rear holes probably also need to be plugged up to quiet down the car as well, but probably not as dramatic of a difference vs. the front holes considering that they are on a flat plane and less turbulent air is there (being farther away from the tires), and also the fact that the holes are much smaller than the front holes.

Great info everyone--will update once I get a chance to plug my holes up this week. This board is great for collaborating info.

ddarbs55

I LOVE CL!!!
i've been complaining about this since day one i bought my car brand new off the showroom floor.
i just took a look, and sure enough, the passenger side hole is unplugged. i just had my car in
for normal maintenance and asked them to check the underside for some grunting and creaking
coming from the undercarriage (sounds like my sways are loose after initial install). no one told
me about the drain plugs not being there. guess i'm heading back to pick one up. i'll seal those
puppies so neither will come of again.
you guys are awesome - thanks again for the info!!

mdw131

I had the leaking window issue too...Turns out the passenger DOOR was out of alignment...The dealer adjusted it and its been perfect!!

doug_999

Something tells me that the rears are not supposed to be plugged - that they are there for drain purposes. No clue how we find out for sure as I'll bet the dealer doesn't know either!

3dog

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som

i checked my wifes 1999 gs400 a few minutes ago and the front holes are plugged and the rear ones are not. this may explain why i have always felt my car was a bit noisy at freeway speeds. i always thought it was because of my coilovers.

thanks for bringing this subject up.

looks like i'll be calling the lexus dealership.

ivan
3dog

SeattleGS400

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DJC:

Just curious, what were the part numbers for the silver dollar front driver's and passenger side drain plugs that you had replaced a while back?

I have a floorpan schematic from the dealer and they are not totally sure of which one. From the pics, it looks like the part number should be:

90950-01959 (silver dollar front driver's and passenger rubber plugs; 100% fit; $3.09/each)

Also, the plug for my rear frame member holes looks like either of these part numbers:

90950-01580 (most likely as the schematic lists 4 per side)
90950-01710 (it's a possibility as well as the schematic isn't totally clear)

Note, I just tried, and it's not 90950-01755 (too small!) for the rear frame member.

DJC

SeattleGS400 - I found the service invoice when the plug was replaced and it has no part number recorded. It states the description of the work performed, but no part number.

chicagoblknazn

I solved my problem...I lifted the drain tubes in teh trunk a bit and it stopped. They still slip a bit every day when I drive so I am going to use a lil bit of silicone to keep it pushed in a bit.

SeattleGS400

iTrader: (1)

With the drain tube, access it from the trunk (located at the side pockets where the jack is kept and you'll see the drain tubes), pull it straight up, then just get a couple of medium sized rubber bands and wrap it around the drain tube and reinsert it back into the hole. It will stay up really well. I only left about 0.75 to 1" exposed and hanging back out the car.

You'll find pics of the rear drain tubes accessed from the trunk here:

https://www.clublexus.com/forums/sho...hreadid=109594

Note that in the pics, I haven't added the rubber bands to them yet, but you should get the idea.

Glad your car is fixed.

SeattleGS400

iTrader: (1)

Bummer, I was hoping to get the part numbers from you. There is something you can do--when you call the dealer for a service history (by giving them your VIN), they can look up the work done, and it lists the parts they used in the repair (even if the invoice that you have doesn't).

But then, who knows, I may very well have gotten the right parts, but we'll see. . .

SeattleGS400

iTrader: (1)

INSTALLATION UPDATE

I just got the rubber plugs from my Lexus dealer and 2 plugs are exact (the fronts), while the 2 rear plugs I ordered were off (the top inner locking attachment is a bit small)—see my post above for the part numbers and costs. The plugs are in the pic below (the 2 top plugs are for the front--the left side is the top, and the right side is the bottom of the plug).

Anyways, I prepped the surface of the underbody with rubbing alcohol and let it evaporate off. To make sure that the plugs were going to remain secure and seal the holes, I used some “Permatex Weatherstrip Cement” ($3.99) on the top contact surfaces (RTV silicone would have worked just as good). It’s simple to install the plugs—put a little cement on the upper lip of the rubber plug, and just push them in the hole.

The fronts were very easy and they fit nice and flush with the underbody. The glue countermeasure should make this a permanent fix.

While I got the wrong part for the rear holes (see a few posts above on what to get instead), I ended up just using them with lots of weatherstrip cement to secure it (using tape as a temporary holding support while the glue dries). If the rear plugs fall out, I’ll look to order the other rubber plug part numbers so they actually fit properly.

IMPRESSIONS

My car is noticeably quieter—all that I hear is the tire and some road noise. My car does not seem to be as loud as before, and I don’t get a “gushing wind” noise over smooth roads over 40mph any longer. I haven’t tried driving my newly plugged up car on the freeway, but based on the in-city results, I would imagine it would be much quieter than before (less road noise and wind noise permeating inside the car).

If I find out anything different, I’ll be back with an update. So far, so good.

Thanks DJC for starting up this thread, as I initially discounted the idea of a missing body plug in my car—but sure enough, that was the issue at hand! And of course, thanks to everyone else helping to figure this out

SeattleGS400

iTrader: (1)

Here's a pic of the plugged up front driver's side hole. It fits great and covers up the with a nice snap--the passenger's side fits very nice as well. Again, use some silicone adhesive or some weatherstrip cement adhesive to ensure that these plugs stay on the holes permanently. In the pic, you'll see a glue interface around the outer black rim of the rubber plug (glue between the top surface of the rubber plug and the underbody sheetmetal).