Water Leak Under Rear Carpet

Eric5412 · December 14, 2004

I'm having a problem with water somehow leaking under the carpet on the driver's side rear. About 2 week ago I was running some wires for my stereo, and noticed that the foam underside of the carpet was soaking wet. I checked door and window seals, trunk seals, and I even sealed the rubber plugs from the outside with sealer because they felt a little loose. It is only getting wet from the bottom of the carpet, the top is completely dry and no other place in the car is wet(that i can see). I have no idea how long it's been getting wet.I only noticed because I had the carpet out . There's a slight moldy/mildew smell already. I have dried it out and after heavy rain it's wet again. It’s not from the AC,haven't used it since summer and it's not antifreeze.I recently had the moonroof seals replaced by Lexus, which was dripping into the car. Could that somehow be related to my problem now?I would like to fix this myself,if I can.I had such a bad experience with the dealer,I would hate to have to return there,even if it's their fault.I have read other posts about the moonroof drains, Where exactly are they? I only could find 2 in the front corners, I heard that there are 4. Where do they drain to? If they are clogged would that cause water to get under the carpet? I thought the seal around the moonroof glass stops water from getting in, why are there drains?

gbhrps · December 15, 2004

Eric5412,

The sunroof seal can only stop MOST of the rain. Some will leak past it, and that is what the other drains are for. There are 4 drains for the sunroof, one each side at the front that have a hose that runs down the inside of the A pillars. There are another pair at the rear, one each side, that I suspect go down the C pillar. I say "suspect the C pillar", since my 97 workshop manual doesn't mention or show any hoses in the B pillars at all, and I see what I suspect is a drain hose exiting the C pillar into the side of the rear wheel well on page BO-78. Where it is shown on the 2nd diagram of that page, if the hose has come out of the wheel well opening, the water will definitely drain either into the trunk, or more likely the rear foot well. To get at it, you'll have to pull the rear seat bottom and back, and then the side panel over the wheel well. That said, the other place that water gets in frequently, is from around the rear tail light seals. It is possible that it puddles in your spare tire well, and some could find its way to your rear foot wells too. Might want to check the trunk out. Hope this gives a start. Good luck!

shahab_b · December 15, 2004

Eric5412;

I know how you feel man , this happened exactly for me last week , I had to take the back seat out , open the carpet and it was just water everywhere , its actually still wet , I am still changing the towels everyday!!

I checked the sunroof drains and one of them was full of dust and that was why it leaked somehow underneath the driver side front and back.

temporary solution : get a dock tape , dock tape all around your sunroof for now , and dry your carpet out , and later check the drains , get a spray and open them up , I am sure its from the sunroof , cuz when I dock taped it , stopped leaking !!! and it was just the carpet and the foam which was wet!! good luck !!

Eric5412 · December 15, 2004

I just pulled the spare it it's dry,the whole trunk is dry.It sounds to me like it's my rear drain that's the problem.I'll have to pull my rear seat and trim out and follow that hose.Anyone know if there is a uv dye that I could mix with water and maybe trace with a blacklight(nothing that would stain my light gray headliner),like they have for oil and trans.?<shahab_b----To help dry it out you could reach under the drivers seat and pull the carpet over the heat vent on the floor and place something under the carpet to "tent" it up some and drive with the heat on fooor,that's what I did worked pretty good,but I didn't have 2 inches of water>Thank You for your help,please let me know if there's anything else I should check.

gbhrps · December 16, 2004

Eric5412,

You're going to have to devote some time to tracking down the source of the leak, and water leaks can be a b**** to trace. I agree that your source has to be from the sunf roof, and most likely that one rear drain is plugged up, or has come undone from its gutter up top. The only way to get to the problem is to pull down your headliner and go from there. To do that you'll first have to carefully remove all of the A, B and C pillar mouldings that go around the top openings of the doors. A and B pillar mouldings are just on with spring clips that you pry off. Remove the interior room light lens and the screws underneath. Remove the roof side handle assist straps, the sunvisors, and the front centre roof console that houses your reading lamps and sunroof controls. Finally there are 3 clips along the upper part of the rear window, and the headliner is ready to drop out of place. I suggest a second person to help you remove it from the car if its necessary. Now you should be able to use compressed air to blow out each of your drains, or run a stiff wire through each. For sure you'll be able to stay in the car while someone runs a water hose over the sunroof, so you can watch for where the offending water is getting in. Take your time, and you'll solve your problem yourself without spending any money, and you'll have the satisfaction of having done it yourself. Obviously, putting the headliner back in is the reverse of dissasembly. Good luck!

kristiad · December 16, 2004

I had this problem on the front passenger side. I have been told that Lexus has this problem on the es300. My car is a 2003. The carpet and the carpet pad had to be replaced. After a lengthy discussion (and explaining that I am a lawyer) it was replaced under warranty. Otherwise, it would have been $1400. Don't let them blame you for this problem.

quote=Eric5412,Dec 14 2004, 07:52 AM]

I'm having a problem with water somehow leaking under the carpet on the driver's side rear. About 2 week ago I was running some wires for my stereo, and noticed that the foam underside of the carpet was soaking wet. I checked door and window seals, trunk seals, and I even sealed the rubber plugs from the outside with sealer because they felt a little loose. It is only getting wet from the bottom of the carpet, the top is completely dry and no other place in the car is wet(that i can see). I have no idea how long it's been getting wet.I only noticed because I had the carpet out . There's a slight moldy/mildew smell already. I have dried it out and after heavy rain it's wet again. It’s not from the AC,haven't used it since summer and it's not antifreeze.I recently had the moonroof seals replaced by Lexus, which was dripping into the car. Could that somehow be related to my problem now?I would like to fix this myself,if I can.I had such a bad experience with the dealer,I would hate to have to return there,even if it's their fault.I have read other posts about the moonroof drains, Where exactly are they? I only could find 2 in the front corners, I heard that there are 4. Where do they drain to? If they are clogged would that cause water to get under the carpet? I thought the seal around the moonroof glass stops water from getting in, why are there drains?

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amf1932 · December 16, 2004

I had this problem on the front passenger side. I have been told that Lexus has this problem on the es300. My car is a 2003. The carpet and the carpet pad had to be replaced. After a lengthy discussion (and explaining that I am a lawyer) it was replaced under warranty. Otherwise, it would have been $1400. Don't let them blame you for this problem.

Did you ever consider that the car in question no longer has the Lexus warranty? I did notice that the poster didn't mention the cars year.:whistles: