2006 GS430, 175k miles. I've been dealing with a leak for the last 18 months. The water comes in to the cabin through the overhead console, in front of the sunglasses holder. I initially thought it was coming through the windshield, so I sealed the windshield with black electrical tape, yet the water is still coming in, so I can rule out the windshield as the culprit.

The only other way water can get in is through the moonroof. With the moonroof closed, I can feel that there is some water in the channels, but here's what I don't get. My drain tubes are not clogged. I have flushed them with water and the water drains through tubes and out the bottom of the car just as it's supposed to do. If there is water coming into the car through the moonroof, so what??? Shouldn't it flow through the channels and drain out the drain tubes? I am just not seeing how water that gets into the car through the moonroof can somehow end up in the cabin. There is no place for the water to get into the cabin through the moonroof. The moonroof casing is a one-piece solid unit. The only way out is through the drain tubes. I am really stumped.

Any ideas?

 

Burn the car... you have been dealing with this far too long

 

LOL, but I love the car. I did some Internet searching and apparently I’m not alone as it’s an issue with other Lexus models as well. The problem us that no one seems to be able to identify a fix. The biggest misconception is that people think that water shouldn’t get past the moonroof seals. That’s wrong, it should and does and that’s the reason for the drain tubes. But if the drain tubes are not clogged, then how can water be getting in the cabin through the overhead console. And we know it’s not the windshield because I have it completely sealed off with tape.

 

I understand that the sunroof has a gasket replacement available. It's installed without any disassembly. Sometimes parts changing is the best way to diagnose/resolve a problem. Have you replaced the gasket yet? BTW why would someone say you've been dealing with this for too long? Have you run a thread once before? If so, I can't imagine you haven't heard my suggestion before.

 

I think he was being sarcastic. But yes, I had posted on a different thread how I thought it was the windshield, but now that I have sealed off the windshield and I’m still getting water in the car I realize that it can’t be the windshield.

As for a new gasket around the moonroof, sure, we can try that but again, assuming the drain tubes are not clogged, which they are not, then any water that is seeping past the gasket should drain out through the tubes and out the bottom of the car.

What I’m saying is I don’t see any place in the moonroof assembly where water could get in. Let’s say that the drain tubes were blocked. In that case, the water would back up in the channel and come in over the lip of the inside of the headliner onto the gearshift for example, but not through the overhead console. There’s just no path for the water to get there from the moonroof.

Does that make sense?

 

Sometimes things don't make sense or we can't see/detect the problem. Good luck.

 

I had a 97 LS400 which was leaking into the cabin from the moonroof. One of the drain tubes had come loose from where it connects to the channel in the moonroof underneath the headliner, allowing the water to leak into the car. I discovered it by blowing compressed air into each drain individually, and I could hear the air coming out underneath the headliner.

 

Thanks for the reply. I’ve poured water into the channels and the water flows out through the tubes out the bottom of the car so I’m sure the tubes are still connected. I’m literally stumped.

 

i wonder if one of the tubes could be cracked or something. how much water is actually coming in, say when it is raining out? just a couple drips? or a bunch?

Also, how fast does the water in the channel drain out of the tubes? is it fast, or does it take awhile? it still might be worth blowing the tubes out with air. mb they are partially clogged, and can't keep up with the water getting into the channel on rainy days, causing it to overflow and leak.

 

The water drains immediately when I pour it in there. Also, the water is leaning in through right in front of the sunglasses compartment, so right in the middle. If one of the tubes was broken, I would think the leak would manifest itself in the corners or on the carpet, right?

 

I wouldn't rule out a faulty/cracked drain tube. Just because it's flowing, doesn't mean it's still not letting some water pass by. Honestly, I'd personally just use a day off to go in and replace the entire tube all together. It's not the easiest job, but definitely not the most difficult. Replacement parts are pretty cheap as well. If that doesn't do the trick, I'd be looking around for rust spots and gaps within the moon roof. Hope you get to the bottom of this, I know I'd be really annoyed.

 

But if it was a broken drain tube in one of the front corners of the moonroof, how would water migrate up and over to the middle of the roof and come out through the overhead console (the car is always parked on a flat surface). It seems to me that a cracked drain tube would result in water coming down the side of the car and maybe puddling in one of the foot wells.

My next step will be to seal the moonroof with tape to see if that eliminates the leak. If so, then I’ll know for sure that the water is coming in through the moonroof and then somehow getting into the cabin (although admittedly I still won’t know how at that point).

Thanks a lot for all of the suggestions guys. Much appreciated.

 

I looked. There is a square taped black pad in the front moonroof channel.
I don't know what it is for. It's directly above the console. Can the water leak through that pad?

 

Fantastic question. I wondered the same thing. I assumed the tape was just a piece of felt to cushion the roof when it closes. I didn’t want to peel it off (because I was afraid I wouldn’t be able to get it back on), but I assumed that there wasn’t a hole behind it. It is always wet when I feel it after it rains.

 

have you pulled out the overhead console? i think i would do that next at this point.