Water Under Carpet In Driver's Footwell

[rrr]

Hi,

I have a 1999 Gs300, 85k mi. Just noticed the carpet was wet in the driver's footwell. I pulled back the carpet, and the carpet and insulation under it is completely soaked. Smells like basic water, no noticeable color. My first thought was that the heater core is leaking, but that would be strange since the heater core is (normally) on the passenger side. Checked the coolant tank, and it is full. I haven't been in any heavy downpours (that I remember), or driving thru puddles, but we have been driving in some light rain/wet roads. I did wash the car, but I don't know if was wet before I washed it.....

I pulled up the carpet as much as I could and ran a small fan over it for 4 days, and the carpet is dry again. There must be a reason...it will happen again....

Anyone had a similar mysterious situation?

thanks!

[new big400]

Have you been running the air?This is just a sugg. but I talked to a guy who had a similiar prob. and it was a plugged air cond. line.

[TurboGS300]

Did you wash under the hood when you washed the car? More than likely when you washed it water leaked in through a missing body plug or hole that may have been drilled for something aftermarket. I think the AC condenser is on the passenger side, if it is it rules out the ac leaking as big400 mentioned. <_<

[GuyTelefunken]

The heater core would leak antifreeze, not water.

There are several possibilities.

1. The evaporator drain may be blocked. There is a hose located about the center of the car under the evaporator case, directly behind the radio at floor level. The hose can be seen under the car.

2. The air inlet cowl (grill around the wipers) drain may be blocked. If you remove the wiper arms and the plastic grill around them, look for the drain at the lowest point in the box. If you run water down the windshield it drains into this air box. If it fills too full because of a blocked drain/debris in the box it can overflow into the air intake for the HVAC system. This fills the evaporator case and you get a wet carpet.

3. Windshield seal is leaking. Check the other possibilities first. If all the drains are clear you need to get one person in the car under the dash with a flashlight and someone else outside with a hose. Remove the panels under the dash and pull back the carpet. Run water down the windshield at each side (hood closed to simulate normal rain conditions). You should be able to discern the location of the leak visually running down the firewall on the inside if it is the windshield. If this is the case, it's best to contact a glass shop. They may recommend sealing it in place or removing and resealing/replacing the windshield. Keep in mind that sometimes the windshield will break when removed.

Side note: In my shop we dread leaks of this nature. They are time consuming and sometimes difficult to correct completely. It is not common for this to happen in a Lexus (or any Japanese car) so check the obvious causes first.

[GuyTelefunken]

Did you wash under the hood when you washed the car? More than likely when you washed it water leaked in through a missing body plug or hole that may have been drilled for something aftermarket. I think the AC condenser is on the passenger side, if it is it rules out the ac leaking as big400 mentioned. <_<

←

Clarification: The condenser is in front of the radiator. The evaporator is in the center of the car, parallel to the firewall.

[cruznroadking]

I agree wil Guyt on the evaporator drain hose being blocked. I've even seen this hose fall off causing the water & condensation to leak inside the car. This is usually a rubber hose.

[new big400]

Thats the prob. my buddy had was had was a blocked evap. hose.

[rrr]

Thanks everyone for your ideas. This forum is a great source of info!

I've tried all of the ideas, but everything looks ok. :(

The evap hose is not plugged (I blew air into the hose from under the car (with my mouth), and it was not plugged (air flowed very freely)).

The drain under the wipers was not plugged (I poured some water into this area, and the water quickly flowed out onto the ground thru the drain hole).

Sunroof drains also were not plugged.

All grommets look fine (I put the car on ramps and checked them all).

I then washed the car, spraying everywhere (under the car, in the wheelwells, at all sides of the windshield, at the door seams, etc), and nothing...

So now I'm really baffeled. The only far fetched idea is this: 1 week ago my wife had the car in a local shop for a smog check. Am I out of my mind, but is it possible that they poured water in the footwell to inspire new business? I'm not usually such a pessimist, but I'm running out of ideas. Ever heard of such a thing? :o

Thanks again everyone. I put it all back together, and I'll check it from time to time to see if it happens again.

[TurboGS300]

You didn't say whether you looked under the hood for any holes drilled in the firewall or any grommets missing or not fully installed on the firewall . <_<

[rrr]

You didn't say whether you looked under the hood for any holes drilled in the firewall or any grommets missing or not fully installed on the firewall . <_<

←

Yes, I looked under the hood. All looks in place. No aftermarket stuff has been added. Thanks for your suggestions!

[rrr]

Problem solved.... :cries:

Thanks to all the suggestions, but the problem is with the plastic air cond box under the dash, leaking at a seam in the box. The AC drain is working properly, but the seam leaks enough to give a steady drip, drip, drip.

What a terrible design for a box that is designed to collect water: it is built as 2 halves of a box, screwed together, with a seam at the bottom! The 2 halves are held together with 3 screws, but tightening them does not stop the leak. I expect a bad gasket, or the plastic box is cracked in this spot. There is no way I can replace this myself, it's too buried under the dash. I'm afraid to guess at what this repair is gonna cost from the dealer.... any guesses???

I expect better than this from Lexus.

By the way, I had to replace 2 A-arms at 70k mi due to failed rubber bushings. Is this the Lexus quality I read about in the press??

[TurboGS300]

Good job on finding the leak! Can you use an RTV sealant to stop the leak? <_<

[SKperformance]

First why is yorus leaking?

Is it because a drain line is clogged?

Did a previous owner park under a tree with lots of sap ,if so it would have melted down and clogged a drain causing a problem .

Until you know why it leaks you can;t place blame on a bad design.

If it was all about design on Lexus and them being responsible the you could say every owner who gets in an accident should blame lexus for not building a car to never get in an accident.

know what i mean?

[Win Lowe]

RRR: You did well in finding that leak; I would try some JB weld or epoxy to fix that leaky seam, they are really excellent products for this type of use. This could be one of those problems that the fix is a piece of cake compare to locating the cause.

I can understand your feelings regarding the quality of Lexus but little things like this happens to the best of them, remember nothing in is prefect. Stay cool and mark this one up as a win for yourself.

Win