2006 Rx330 Water In Floor

[CUTiger80]

I have been chasing this water leak for some time now. The car is my daughter's and she has it away at school. Finally traded cars with her so I could spend an extensive amount of time chasing this down.

I have removed most of the trim around the door threshold so that I can prop the carpet up away from the metal floor to dry it and to see what is going on.

I thought it was related to the moon roof. Checked all 4 drains and they are working fine. Sprayed a heck of a lot of water on the roof last night, around the moon roof, and at the seam above the doors. There was no water on the floor under the carpet. Got about 1/4" rain overnight and checked this morning. Again, no water on the floor under the carpet. I placed a washcloth on each floor board right on top of the drain plug so that it would be easier to tell if there was any water getting in.

Drove the car into work (20 mi.) with no rain and only slightly damp roads. I ran the A/C full-time to dry to finish drying the carpet out. When I got to work all 4 floors had some standing water and all of the washcloths were soaked.

I had put some rags where the "B" pillar meets the floor on both sides because my daughter had said that she had noticed the seat belts were sometimes damp. Both of these rags were wet as well.

I have checked around the hatch and where the spare tire is and all of this area is bone dry.

Any idea of where this water may be coming from?

Any ideas on what to check next?

[zieke]

It sounds like the a/c drain is either disconnected or there is a hole in the drain hose. See if water drains on the ground when the a/c is running. It should.

[CUTiger80]

Steve,

Thanks for your reply. This has been a frustrating situation to deal with, especially from a long distance.

I will try and check this tonight. Do you know where the drain comes out?

If it is the drain, is it reasonable that water would get into all 4 floorboards?

[lenore]

The drain itself comes out on the firewall between the engine and firewall on the passenger side of vehicle. you would have to look from under the car. It is usually a little black rubber hose.

[VBdenny]

Sounds like a heater core failure. They leak onto the passenger floor and spread. I can't see how an '06 could leak but stranger things have happened.

[lenore]

ah you may be on to something, maybe the heater water control valve is leaking or a hose connection....

[CUTiger80]

I gathered a little more information last night and this morning.

Last night I checked the cabin filter behind the glove box and it is bone dry.

I placed a small washcloth in all 4 floorboards. I also stuffed a small towel up in the molding where the "C" pillar meets the floor on both sides. I removed the plastic trim around the bottom of the passenger side "B" pillar and stuffed a rag where it meets the floor.

I left the car parked slightly uphill last night and we got over 2" of rain; that intense pouring down scary stuff we get in the South this time of the year.

I came out this morning to find about 8-10 ounces of water standing in the rear driver's side floorboard. The towel that I had stuffed up in the bottom of the "C" pillar was also soaked. The other 3 floorboards and towels were all dry, including those that I had stuffed at the bottom of each "B" pillar. I dried out the water and then placed a large folded beach towel between the carpet and metal floor on the rear driver's side and drove to work with the A/C on wide-open (temp as low as it would go and fan as high as it would go).

When I got to work (20 miles or so) I found standing water in all 4 floor areas. The beach towel was totally saturated. Both of the towels that were stuffed at the bottom of the "C" pillars were soaked. The carpet around the bottom of the driver's side "C" pillar was also soaked. If I had to guess, I would estimate that I sopped over a gallon of water out of the car. I opened the hatch and pulled down the headliner at the rear and the top seemed dry. I checked the A/C condensate drain and I saw several drips come out of it, but the engine was off and had been for 5 minutes or so.

The leak is not related to the heater coil (as others have suggested) because the water inside the car does not have anti-freeze in it. I doubt that it is totally related to the A/C condensate drain, but that may be contributing. I still have to rule that out.

My plan is to remove the back seat and the trim around the base of each "C" pillar to see if I can determine what is going on.

I would also like to remove the headliner, but I am afraid that job (and the replacement of the headliner) is too big for me. Has anyone done this before and can verify whether it is as bad as it looks?

I also want to try and seal up the moon roof from the top (possibly with duct or painter's tape) and spray water on the roof to see if it is related to the moon roof drains or something else (like a leak in one of the body seams).

Any other suggestions (other than taking it to the dealer or selling it) would be appreciated.

[VBdenny]

Every time I've ever removed a headliner it involved removing the seats. Never did an SUV though. Time to break out a hose, a friend and a flashlight. Has any of the glass on the car ever been replaced?

[CUTiger80]

Denny,

Not that I know of. We have only had the car for 2 years though.

That's the weird thing. Spraying water on the car does not seem to make it leak. It is only when it has been driven, leading me to believe that water is being "stored" somewhere and then running around when the car is driven. Like I said in my post above, after over 2" of rain last night I only had about a pint of water in the car. Once I drove it for 20 mi. or so, I had over a gallon in the car.

[lenore]

Have you looked under the trunk floor. I wonder if it is full of water....

[CUTiger80]

Thomas,

I have looked there and it is bone dry.

I have everything (except for a few spots on the carpet) dried out now and have run the A/C hard for 40 miles or so with no noticable moisture in the inside of the car and visible dripping from the condensate drain tube under the car. i think this rules out anything related to the A/C.

I am going to run some tests this weekend and try to isolate whether the leak is related at all to the moon roof drain tubes. The tubes do drain when I pour water into the channels on each side, but they may also be leaking. I figure if I pour a lot of water into one channel/tube at a time, I should be able to tell.

My next plan is to seal up the moon roof with plastic and duct tape and thoroughly wet the top of the car to see if it may be coming in from a body seam or something like that.

I think eventually I am going to have to remove the back seats and the trim from the lower portion of the "C" pillar to figure it out for sure.

[zieke]

Based on everything that's been said, I'm fairly sure the car has been wrecked and not repaired in a timely manner. I chased a small leak in the trunk of my old RX 300. It took awhile to find, mainly using trial and error but I had it narrowed down. Mine had been hit in the rear. Don't know if I'd be too excited about keeping the vehicle because of other probs that are likely to occur down the road. Good luck.

[CUTiger80]

zieke,

You way underestimate my resolve. I don't give up that easily. If I can take a car that I got a really good deal on and make it better than average, i consider it a "win".

I didn't have much time this weekend because of other commitments, but this is what I did do.

On Friday evening I think that I eliminated the rear moon roof/roof drains. I poured 2L of water into each side channel and I got exactly 2L of water out at the drains behind the rear tires.

On Saturday morning, I removed the left rear seat and pulled the carpet back under it so that I could expose the metal floor pan under the carpet. This is the first place it seems that the water gets in and then spreads throughout the car.

Yesterday, I sprayed water all over the windshield and the front cowling to try and eliminate the windshield, its seal and the front drains. I got no water in the car. I then progressed little-by-little further back, focusing primarily on the left side where I had removed the seat. I sprayed water on the top and side of the car for probably an hour (off and on) and did not notice a single drop of water in the car. Based on previous experience that my daughter and I both had in the car getting wet but not noticing water in the car until it was driven, I decided to drive the car around the block right before dark. When I slammed on brakes I heard a distinct "swooshing" sound of water flowing. I immediately stopped and the area under the left rear seat was very wet. The water had flowed out of the trunk area from a space that appeared to be below the trays that hold all of the jacks, etc. I also had water on the rear passenger side right beside the "C" pillar. I had stuffed towels in both locations to prevent any water from spreading.

My next step (it will be later in the week before I have a chance to work on it again) will be to remove all of the flooring in the rear and the plastic trays to see if I can tell where the water is actually coming in. The top side of the plastic trays are bone dry.

Based on a suggestion on another forum, I first may try saturating the area around the left taillight to see if the taillight seal is indeed the culprit. I will certainly report back what I find. I feel like I'm getting close to solving this puzzle.

Thanks to all of you for help and for reading thought my rather lengthy explanations. I'm an engineer and I am programmed to solve problems methodically and logically. (My wife thinks I'm an alien when I get into this mode. I guess methodic and logic doesn't apply to baking a cake.)

[CUTiger80]

Update.

This is what I found over the weekend.

I pulled out all of the access doors and plastic trim in the rear cargo floor area, all the way down to the sheet metal. I sprayed water all around the left and right rear areas, concentrating on the hatch and tail light areas. I was able to determine that it was leaking around the left rear. I continued to narrow this down until I could determine that it is leaking around the seal between the left tail light assembly and the body. I pulled out the tail light assembly and visually inspected the gasket. It does not appear to be torn or rolled or crushed, but it seems that this is the only place where water can come in that area. I've decided to go ahead and replace it, but I can't seem to find one on the internet at any of the parts places. Does anyone know if this is one of those "dealer-only" parts? Thanks again for all of your help in getting to this point. I will continue to update this post as I (hopefully) finally solve this problem.

[1990LS400]

I think it is part # 81552-0E010

Google it and see if it looks like what you need.

Worse water leak I've ever had in a car was caused by an improperly installed driver side taillight gasket on a Honda Accord.

[CUTiger80]

1990LS400,

I think that is the correct part #. It appears to fit either side (I guess it is reversible).

I can get if for about $25 from LexusPartsNow.com. I'm going to see what it would be from my dealer or from a friend I know that does some body work.

Thanks a BUNCH for your help!

[1990LS400]

It is a different part # for the right taillight gasket - not reversible. I found the left side gasket online for as little as $12 not including shipping.

I'm getting the part numbers from www.toyodiy.com but you have to register to see the diagrams.

[CUTiger80]

Jim,

Thanks again for your help.

I did register at toyodiy.com. It is kinda strange the way the part is listed. In the list of parts, it calls out the RH & LH gaskets, but if you look closely at the part numbers listed, it is the same for both. There are 2 numbers shown. The RH part has the number "81552" but below it appears the part number "81552-0E010". The LH part has the number "81562" but below it appears the part number "81552-0E010"

The part online is a little over $12, but S&H is about the same making it about $25.

I called my Lexus dealer and ordered the part for $19.

I'm wondering now if the LH part is listed incorrectly and it should be "81562-0E010"???

[CUTiger80]

Jim,

I called the Lexus dealer parts department back and they confirmed that the same part fits both sides. The "81562" number is just a reference code and it is unique for LH. They indicated that the reference code for a part is sometimes a part of the actual part number, but if there is a part that fits both sides, the first number (or the one that starts with the reference code) is always the RH side. Good information to know in general going forward.

Thanks again for your help.

I will post some results in the next few days after I have had a chance to install the part and test it.

[1990LS400]

1990LS400,

I think that is the correct part #. It appears to fit either side (I guess it is reversible).

I can get if for about $25 from LexusPartsNow.com. I'm going to see what it would be from my dealer or from a friend I know that does some body work.

Thanks a BUNCH for your help!

If it is the same gasket on both taillights then you could do a test by swapping the gaskets from side to side and see if you can move the leak to the right side or still leaks on the left side but not on the right side.

I suspect that it is not a taillight gasket problem since taillight gaskets are not being subjected to frequent compression/decompression like a door or trunk lid gasket is. I wonder if there has been collision damage to the taillight area and if the metal body work is deformed and not allowing the taillight gasket to seal.

You might be able to see if this is the case by inserting a length of fishing line or dental floss between the gasket and bodywork and between the taillight module and the gasket and then reinstall the gasket and taillight. Work the fishing line or floss around the gasket to see if there is resistance at all points - might indicate if there are small gaps. If this was a door or trunk lid gasket I would use one inch wide strips of decently strong paper to verify that the gasket is making adequate contact (i.e. resistance when the paper strip is pulled but without tearing the paper) but I doubt if paper strips would work to do a test on your taillight. The paper strip testing method may sound silly but it was documented in the shop manual for the last Mercedes I owned.

If all else fails, maybe apply a healthy bead of clear silicon caulk on both sides of the taillight gasket.

[CUTiger80]

Jim,

Thanks for the suggestions.

Since the tail light assembly is a pain in the !Removed! to remove/replace, I will wait on the replacement gasket. I would hate to create a leak in the right side where one does not currently exist.

Also, the design of the assembly and how it fits so tightly in the vehicle quarter panel pretty much excludes the test with the fishing line or dental floss.

When I removed the tail light and gasket yesterday, I did a pretty thorough visual inspection of the area where the gasket contacts the body and either the painter did a real good job or the panel is original. It sure looks original, but I will inspect again even more closely.

When I do replace the gasket, if that does not solve the problem, I may try doubling up the new and old gasket to see if that makes a difference. And, if all else fails, I will try some silicon or Form-A-Gasket between the gasket and the body panel.

[CUTiger80]

I finally received the new tail light gasket and installed it last night. To be on the safe side, I applied some RTV silicon between the gasket and the body panel. I assembled everything, gave it a couple of hours for the silicon to "set" and tested it. It did not solve my problem (dang!!). The water is not coming in from around the tail light opening.

When I test with water, I have been pouring it down the channel that is between the hatch gasket and the body or quarter panel, about 2/3 of the way down from the top of the car. Most of the water runs behind the black plastic trim piece that is mounted in this channel adjacent to the tail light. There are little plastic fingers on the tail light that actually fit into this piece of trim. Does anyone know if it is normal for water to run down behind this piece? Would I be wise to apply some more RTV silicon at the top of this piece to seal the gap between the top edge of the trim and the hatch channel?

I will keep pressing on until I figure this thing out.

[1990LS400]

Can the water be seen entering the interior by someone sitting in the cargo area while someone else pours water on the exterior? Did you say that you had removed the relevant rear interior trim? If so, I would think that someone could see exactly where the water is entering.

Or maybe try the paper strip test I mentioned previously. That involves cutting a number of 11" by 1" strips of paper (typing/printer paper works well), closing the hatch on the strips of paper and then pulling the strips out to see if there is friction between the rear door and the gasket at all points around the door.

Something else that can cause leaks around the rear door is when cargo causes the rear door or door hinge to bend even slightly when the rear hatch door is shut - particularly a problem with rear hatch doors that have electric power closers. Does the rear hatch door fit evenly around the door frame - flush with the body?

Surely you will figure this out.

[CUTiger80]

Jim,

Yes, I can see the water trail below the tail light right where the vertical portion of the quarter panel meets the metal trunk flooring. Because it is in the corner, there is a double layer of sheet metal. The water is running down between the 2 layers (which are separated by about 3/4"). I've never posted any photos on this forum, so maybe I will take one at lunch and try to post it so that it is easier to visualize what I'm referring to.

It doesn't seem to be coming from around the hatch gasket. The hatch door appears to be flush with the body panels that surround it.

I have been doing these water tests with the hatch open, and so far I have been doing them with the piece of black trim in place that I referred to in the previous post. The trim is out now, so I will try the next time just pouring the water in the channel and trying to follow it all the way down (since it was running behind the black trim anyway).

[CUTiger80]

I ran some more test last night with the black trim piece removed. By progressively moving down the hatch channel with my water bottle, It seems that the water is flowing in from a seam that is behind the bumper cover. I basically got to the point where I was pouring water at the junction of the bumper cover and rear body panel and was still seeing the leak.

At this point, I need to remove the bumper cover to investigate further.

Does anyone know if this is a task I should tackle myself or should I take it to a body shop and have them remove the cover? I looked briefly, but couldn't tell for sure what holds it on. To be fair, it was getting dark and I was using a flashlight.