FAQ: Wet Carpet - Interior Leak Problems

98riv wrote:

I have water leaking in the trunk around the bolt for the trunk hinge.  Is the bolt attached to the trunk hinge and what is the best way to seal it?  It looks like the factory sealed it with some tar like material.

Mine leaked there also. I used some clear silicone around the attachment points and that sealed it.

So I ended up loosening the nuts and lifted the hinge and put some seam sealer around the holes. It stopped the water leaking around the bolts, but I am still getting some water coming in around a seam where two panels meet. I'll have to double check the seam in the trunk channel to see if I missed a spot.

The factory seam sealer can dry out and shrink. It's worth looking at all of it. It may need to be peeled off and re-sealed. Seam sealer is cheap! Are you in a hot/dry climate? (just curious)

deekster_caddy wrote:

The factory seam sealer can dry out and shrink. It's worth looking at all of it. It may need to be peeled off and re-sealed. Seam sealer is cheap! Are you in a hot/dry climate? (just curious)

The factory seam sealer was dried out and falling apart, so I had removed the old and applied new seam sealer. I must have missed a spot the first time around. I don't live in a dry climate.

The carpet only gets wet in the small depression directly under the seat, about the size of a text book
firewall to front seat mount, dry
Footwell for back seat, dry
under driver seat dry

There is no evaporator in the center console for the rear seats is there?
Could there be that much condensation in the air vents for this?

We have been having dew points into the 70's

MINIGUN wrote:

The carpet only gets wet in the small depression directly under the seat, about the size of a text book
firewall to front seat mount, dry
Footwell for back seat, dry
under driver seat dry

There is no evaporator in the center console for the rear seats is there?
Could there be that much condensation in the air vents for this?

We have been having dew points into the 70's

What part of your carpet is getting wet.???
Can't tell from your post. It's a bit confusing.
Is it the passenger side where the heater core could be leaking. Does the moisture feel sticky or is it just water.????

It is not wet up front on the passenger side, just under the passenger seat and behind seat and behind in the foot well. I also found some water in the battery well.
It is water not any auto fluid.
Not sure where the A?C evaporator housing drains out.
Up front off the fire wall I hope.
It has been a crazy year with rain in central Pa.

MINIGUN wrote:

It is not wet up front on the passenger side, just under the passenger seat and behind seat and behind in the foot well. I also found some water in the battery well.
It is water not any auto fluid.
Not sure where the A?C evaporator housing drains out.
Up front off the fire wall I hope.
It has been a crazy year with rain in central Pa.

Do you have a Sunroof. The drains in them are known to get clogged and if someone try's to clear the drains with compressed air it will dislodge the drain tubing and cause water to find it's way anywhere it can. Just a thought.
If that is the case the headliner has to come down to fix the problem.

Rickw wrote:

MINIGUN wrote:

It is not wet up front on the passenger side, just under the passenger seat and behind seat and behind in the foot well. I also found some water in the battery well.
It is water not any auto fluid.
Not sure where the A?C evaporator housing drains out.
Up front off the fire wall I hope.
It has been a crazy year with rain in central Pa.

Do you have a Sunroof. The drains in them are known to get clogged and if someone try's to clear the drains with compressed air it will dislodge the drain tubing and cause water to find it's way anywhere it can. Just a thought.
If that is the case the headliner has to come down to fix the problem.

The other thing you may have to do is obtain a replacement evaporator drain hose for the AC drain. A good parts counter person may be able to help you find one that will fit; on the Riv it's the one with a round flat mounting that has 3M trim adhesive donut on it, and a 90 degree elbow, and a spout end that looks like a duck bill. They were used on a number of these cars. You may be able to find one at a junkyard. Over time the adhesive dries and the part falls off -- or shady mechanics take them off your car when it's in for service, to put them on their own (you can glue it on with silicone). On these cars in "AUTO" HVAC mode, the AC runs all the time and for some reason, if the drain nipple is missing then the carpet usually gets wet as you describe. In my experience the $(*#&($* drain hose has to be in place.

If you can not get one through the parts counter or at a junkyard you can make one up with a rubber 12" hose 90 degree elbow, a piece of sheet rubber (think inner tube) and rubber tire patch cement.

THere is a picture on this page that will help a lot in identifying it if it is there and making it up if it is not:

http://www.fixya.com/cars/t20405274-evaporator_drain_line_located

Picture shows such a tube on a '03 LeSabre. It's the same mounting. On the Riv the elbow is a simple 90 degree straight down that ends in a duckbill-looking slit.

FWIW the FSM says to replace the airbag components under the seat if the carpet gets damp.  Seriously, it says that.  According to the FSM, if you leave the window down in the rain, it's enough to damage the airbag system.  Hard to believe anyone would design a car that way, but that's what it says.

From my personal expirience - not sure if it proves anything.
After my airbags deployed in a crash, I got my airbag module replaced, the one under the passenger seat. Airbag warning light went out, the system was Ok, armed and ready to deploy again )
Then I fixed my AC and got soaking wet carpet as a side effect. Still, SRS was Ok for about a month after that. Then, one day, I was driving in a storm - I mean proper storm, with lightnings, thunders and heavy rain - and one particularly thick lightning struck about a mile away. Then I noticed airbag warning light, it was on again. I can't tell for sure if that lightning lit my light, but even if it hasn't, those events were seconds apart. It could be wet carpet, or lightning, or just a coincidence - I don't know. Anyway, I guess I'm lucky airbags didn't explode again )
Next thing to do - visual inspection of the airbag module. I hope I'll find burnt capacitor or something like that and after replacing it SRS will live happily ever after... but something tells me I'm gonna need another module.

I believe I found the drain. I had to get under the car. It is just behind the vertical plane of the fire wall on the passenger side of the tunnel entrance, it is just a rubber tube similar to 1/4" 0r 5/16" fuel line. It is up high & sticks out about an inch or so. Got the replacement gasket, just a foam doughnut. hopefully this will be straight forward? Any input as far as getting a good seal? Is one better to use silicone instead of the doughnut or use both.

DeepFrozen wrote:

From my personal expirience - not sure if it proves anything.
After my airbags deployed in a crash, I got my airbag module replaced, the one under the passenger seat. Airbag warning light went out, the system was Ok, armed and ready to deploy again )
Then I fixed my AC and got soaking wet carpet as a side effect. Still, SRS was Ok for about a month after that. Then, one day, I was driving in a storm - I mean proper storm, with lightnings, thunders and heavy rain - and one particularly thick lightning struck about a mile away. Then I noticed airbag warning light, it was on again. I can't tell for sure if that lightning lit my light, but even if it hasn't, those events were seconds apart. It could be wet carpet, or lightning, or just a coincidence - I don't know.  Anyway, I guess I'm lucky airbags didn't explode again )
Next thing to do - visual inspection of the airbag module. I hope I'll find burnt capacitor or something like that and after replacing it SRS will live happily ever after... but something tells me I'm gonna need another module.

I've never heard of that happening before, but I've often had lightning cause the landline phones to ring. The kind that has a handset with an antenna. I suppose I need to be specific, after all when I was young we had only had rotary dial-up phones, now we've got smart phones.

Minigun,
Your water leak problem sounds exactly like the one I'm dealing with.  Water in the battery well indicates leakage at a body seam around the trunk hinge and then another seam concealed by the rear window rubber surround trim.  I've been wanting to do a write up on this, but haven't gotten to it yet. I doubt that the AC drain is your problem. I've been working on this for an embarrassingly long time.

MINIGUN wrote:

I believe I found the drain. I had to get under the car. It is just behind the vertical plane of the fire wall on the passenger side of the tunnel entrance, it is just a rubber tube similar to 1/4" 0r 5/16" fuel line. It is up high & sticks out about an inch or so. Got the replacement gasket, just a foam doughnut. hopefully this will be straight forward? Any input as far as getting a good seal? Is one better to use silicone instead of the doughnut or use both.

brutusk is right. Pull the rear seat.

I am still having trouble with my 1998 Riviera. The trunk continues to leak and I want to fix this once and for all. Question? Does the trunk hinge have a gasket, or is it just sealed without a gasket and if so, what sealer is used?   There is a lot of mention of the word “seam sealer”, but I’m not exactly sure what that is. Can anyone be more specific when the term “seam sealer” is put out there?  Any additional information concerning sealing the area of the trunk hinge would be greatly appreciated

EyeDoc1,

Please see the write-up of my experience on this issue which follows:
(this is written with respect to the passenger side of the car because that's the side of my car that is leaking most. These instructions apply to the Driver's side as well).

Symptoms:
Damp or soaked carpet in the trunk (Really!).
Standing Water in the spare tire well
Damp or soaking carpet (standing water)  in the foot wells of the passenger rear seat(s) which may extend up under the drivers and passengers seat in the front. It typically doesn't extend into the front seat foot wells,
(If you have water in the front seat foot wells, then it is probably coming from another source other than the trunk. See page 4 of this thread for one fix - there are three or maybe four possible sources for a water leak with that type of symptom).
Water in the battery well under the rear seat.
Windows which fog up in cooler weather.
No smell of antifreeze although the smell of mildew could be expected.

Unbutton the trunk liner as required until you can reach up and find the "Moisture Check Slot" (see photo) on the side of the car where you've got the leak. The slot is about 1/2 inch wide and 2-2.5 inches long(about twice as long as what I've shown in the photo).  If after a rain you find this slot is dry, then your leak may only be from the trunk hinge studs (bolts) - "Leak Zone A" in the picture . If it is damp or wet, then your leak is from "Zone B" - the basin area around the hinge fittings and/or "Zone C" - the body seam under the rear window trim.






The trunk hinge bolts have a vinyl-like washer to seal them. You can see one of them in the photo above. They may leak a little bit, but if you're getting a lot of water leakage, it will probably be one of the two other leak sources which are both "body-seam" related.  I used white latex bathroom caulk as a "body seam sealant" and it seems to be working fine.  I did this because the color matched the paint, not because there aren't better products to use.  It's fall now and it's starting to get a little chilly for latex caulk to cure unless you've got a heated garage to work in.  But there are alternatives which I'll try to describe.



How to fix "Leak Zones" A,B and C  (refer to photos for "zones"):

Leak Zone "B" Body seam under trunk lid
Looking down on the trunk hinge, Imagine the area surrounding the hinge as a sink, or basin that if you were to dam-up with a towel and pour water into should be able to hold a 2" deep pool of water without leaking a drop.
Clean this area thoroughly so that you can inspect to ensure you see nothing that looks like the black lines in the photo above. Also ensure to inspect under the black trim piece shown in the photo because there's a body seam under it and the trim piece doesn't seal it. When it rains hard the water level in the Zone B "basin" could easily rise up to the level of the body seam under that trim piece. Apply your sealant of choice to anything that looks remotely like a seam.  Check your work by damming up the water channel aft of the hinge bolts which leads back toward the end of the car with a towel or other suitable device, then pour water into the "basin" until it rises above the level of the black trim piece. Run your finger over the "moisture check slot". The slot should be dry if you've been successful.This (filling the "basin with water) is also a great way to tell if your hinge bolts are sealed -Leak Zone A" - feel around the nuts on the studs- they should be bone dry.

Leak Zone "A" trunk hinge bolts-
Leave this "zone" alone until you're sure that "Zone B" isn't leaking! Run your finger along the "Moisture Check Slot" shown in the first photo. Is the slot damp or wet? If so, then ensure Zone B is properly sealed. Is the Check Slot still wet after sealing Zone B? Then seal the "Zone C" body seam.  Think about it: Why in the world would this simple joint leak? Is sealing a hole a vexing technical challenge?

I would  not expect much leakage from this source. The vinyl washers (not nylon and not rubber and not some composite) which are used to seal the trunk hinge studs are about 0.005 to 0.010 thick and didn't seem to be damaged until I tried to check them.  It was only then that I started to doubt that they could continue to function because they are so thin and need to be replaced every time the hinge is disassembled or separated from the car body. If I had new ones I would have replaced them. I would recommend leaving these alone.  If you're sure you''e getting water running down the studs, then here's what I recommend:
It's a one-man and a stick job: Get a thin stick about 33 inches in  length. A section of broom-stick is perfect.  Put down some thick tape or cloth to protect your paint finish, remove the nuts from the bolts on one side at a time. Use the stick to hold up the trunk lid when you pull up the trunk hinge to disengage the trunk hinge bolts (studs) then place the studs onto the protective tape. You may be able to get away without the stick depending upon if the car is pointing uphill/downhill or is level.  If you're pointing uphill at all, I think you'll need the stick.  I believe you will probably find there's nothing wrong with the vinyl washers (of course I could be wrong). You will not be able to buy new washers like these. Use a bead of RTV sealant or fabricate something from similar material. I would NOT try to seal the entirety of the hinge plate to the body panel.  Keep the RTV or other sealant local to the hinge stud or you're asking for water entrapment and corrosion problems IMHO.

Leak Zone "C" Body seam under rear window trim:
The back glass window trim will need to be carefully pulled away from the lower corner of the glass to expose the body seam. It only needs to be displaced locally enough to expose the body seam "C" so that you can clean and seal the seam.  I decided to take the entire trim piece off which has made it a bigger job than it needed to be.
The rear glass window trim at the bottom and its corner pieces are bonded together. If you're not careful, you'll break this bond and then they wont fit together well onto the glass without RTV and Tape holding everything together until it cures. This trim piece comes only with a new rear window and is made of Unobtainium - This trim appears to be bonded to the window only incidentally at a couple of places along the bottom of the glass where it has intruded into the butyl/urethane seal when the window was first installed. That butyl/urethane rubber is tough and bonds well - hopefully, you wont find any at the corner trim piece location. I used a combination of putty knife, flat pry bar and screw drivers to dislodge the bottom trim and corner piece as one unit downwards  and toward the rear of the car. If you pry the corner fitting to the side you'll likely tear it away from the bottom trim piece. This is to be avoided.  

Once the body seam is exposed, you should be able to tell that it has been sealed improperly - that's why you've got a leak. In my case, the seam looked like it had never been sealed by anything but paint. When that paint eventually cracked from body flex, it started to leak. Probably not more than a couple years after the car came off the line. I cleaned the area with a toothbrush, Simple Green and water, dried it out with a heat gun, then applied white latex caulk to the seam. The "Moisture Check Slot" tells me that the leak has been stopped.
The next step is to re-install the bottom window trim. I will wait for a warm day then use black RTV to bond the trim and corner pieces with tape holding everything in place until the RTV cures (I hope that works).

This would be a good time to replace the window rubber surround trim which you can obtain at your local auto glass replacement shop. The shop should have some generic rubber stripping which is a pretty good match with the original profile. They'll have to see the original to make the match. It's the same profile that they will have used on the windshield if you've ever had that replaced.  I think I paid about $27 for the length required. The original rubber surround stripping can harden, shrink and curls over time resulting in a mismatch between the stripping and the corner fittings which makes the car look shabbier than it needs to. This rubber surround stripping comes off easily by loosening one end and pulling it off.  It had come loose on my car so I decided to replace all of it instead of just re-bonding it with RTV.


Note:  These "fixes" all require the use of sealants which have temperature curing requirements.  If you don't have a temperature controlled environment, then be sure that the sealant you use will cure at the ambient temperature you expect to see.  Most "sealants" that I'm aware of need warm temperatures to cure - typically around 70 F.. There may be some products out there which are catalyzed and will cure at lower temperatures.  I do not know. I do know that I used 3M body Sealant clay heated up with a heat gun to pack the body seams shown in the photos.  It helped a lot to let me limp through our soggy Northwest winter. I replaced it this summer when it was warm enough with some latex bathroom caulk. It was not the best thing I could use, but I didn't have to pay a body shop to paint it or try to myself.  The pictures above show my car with the latex sealant in place (and it seems to be working well so far).

That's it. Any questions that arise I will attempt to answer by editing this post. I don't pretend to be the expert on this so please let everyone know if you think you have a better idea.

Edit: November 3rd 2018
I'm still getting water into the rear passenger side foot well.  Obviously my ASSumption that the water was all coming from the trunk leak (Zones "A", "B" and "C" was wrong.  I punched out drain holes in the door weather seals in accordance with my write-up of page 4 but am still getting the water ingress.  I will post my findings and a "Zone D" fix when I figure out what's going on.

I was just fixin' to say that I appreciate you taking the time to do a write up, and lo and behold, there it is.  I'm gonna study it.

And study it I did.  I'm just south of you and going to work on "A" first.  Will get my heat gun and putty knife out and attempt to seal the bolt and washer.  Might just try RTV sealer as I've got that laying around.

However, another two quick questions?  Did you have to removed the trunk lid to reseal the four bolts/nylon washers that hold both sides on, and if so, is this a one or two man job?  Second, let's assume the nylon seal or bushing is shot...buy a new one OR just rely on sealer?  I want to do this right the first time and not have to repeat the process.  Many thanks, in advance.

Hello Christen,
I realize the tempation to just "get 'er done" but I recommend that you have patience until I'm done with my write-up. However, it's a one-man and a stick job:  use tape to protect your paint finish, remove the nuts from the bolts on one side at a time. Use a stick to hold up the trunk lid when you pull up the trunk hinge to disengage the trunk hinge bolts (studs) then place the studs onto the protective tape. I believe yo will probably find there's nothing wrong with the vinyl washers (of course I could be wrong). You will not be able to buy new washers like these. Use a bead of RTV or fabricate something from similar material. Everything that I will have to say on this topic will be placed in my "write-up" post. I want the information to be in one place and not spread out over several posts. I will try to get everything written by 10/07/2018.
Thanks.

OK, disregard the questions.  I just finished up the job.  What I decided to do was work on the trunk one side at a time.  I grabbed a pillow that was about 1' X 1' and that's what I used to place in the corner between the edge of the trunk lid and where the rear window essentially "meet".  I placed it right in the corner because I was going to remove ONE HINGE unit at a time.  IMPORTANT: -->Before you start, I suggest you get a water soluble marking pen (commonly called a Vis a Vis pen--or if you don't care about permanence, you can use a Sharpie, because you are going to want to trace the location of the interface of the upper hinge with the trunk lid to preserve the alignment when you remove nuts and reassemble the trunk lid back to the upper hinge.  The water soluble pen's ink is a snap to remove.  You need a 13mm socket to removed 4 nuts...two under the lower hinge where it holds the hinge to the car body.  They are the 2 larger nuts.  Those were easy.  I next disconnected the pneumatic strut.  I took it off the lid, but I don't think it matters.  I used a long stick for additional propping of the trunk lid.  Next I loosened the top nut on the upper hinge that affixes to the trunk lid proper a bit, but then went to what proved to be the tougher nut to undo the lower one.  The bottom nut is at a weird angle to access, but I was able to get it with a 13mm socket, a universal (or swivel), a 3-4" extension and a 3/8" drive with a flex head. A 1/4" drive or a 13 mm wrench might also work, but I lost my 13mm 1/4 socket and the local Sears is closing...this month.  Tight fit, but it took that nut off.  You'll feel the trunk lid shift a bit, but the pillow was invaluable as a buffer to prevent scratch, etc.  Once the 4 nuts are removed, it's pretty easy to wiggle-wobble the hinge off the car body.  I cleaned both mating surfaces with brake cleaner.  I did not have a nylon washer, but a simple black rubber ring that resembled vinyl, as you noted.  This "gasket" seemed to be about as thin as dollar bill, it was that crushed.  I guess I'd have to have a Buick parts manual to see what the correct washer is, but the heck with it.

Once I cleaned the area, i removed some old caulk from the side that you have marked "Location B", I noted it was pretty rusty underneath, so I used my Harbor Freight #62340 Heat Gun (which can mimic summer), which is far superior to your girlfriend's hair dryer, to dry everything out.  I put in a thick bead of Permatex black silicon adhesive (#81158) and used my gloved finger to jam it in place.  That's for Location "B".  For Location "A", i just ran a ring of Permatex Ultra Black gasket maker (#82180) around the bolt holes and proceeded to reinstall everything in reverse order, paying attention to the alignment marks and ensured the trunk lid fit correctly.  Whole job took about 1.5 hours because of the considerable amount of cleaning and prepping to get things just right for the "final sealing". [NOTE: I"m just telling you what products I used. Those Permatex numbers may have been superceded by now with newer products. It's just what I had laying around that seem could or should be able to do the job]

I'm reserving Location "C" inspection if I get any water on the floorboards.

The rains are coming today and I'm hoping for a Pacific Northwest monsoon to either prove or disprove the seal job I just did.  Will let you know if I have a swimming pool, a wading pool or a place for 3 guys to hide out if we ever go to a drive-in movie.  In comfort and style.

Christen,
You certainly got right on it as you said you would. I hope it works out and you don't have to tackle "Zone C".  You might want to re-read my post above which I now consider finished.

Brutusk

Update: Today it was raining. There was water in the back seat foot well behind the passenger seat. I checked the "Moisture Check Slot" per my previous post photo and all around the trunk and it was dry as a bone. Conclusion: These leaks can be very tricky. It turns out that part of the leak problem into the rear foot well is due to the problem which I describe on page 4 of this thread. I will use that fix (drilling a "weep drain hole" in the door seal this weekend when I have time. I will try to post a photo. The good new is that my trunk leaks are a thing of the past and my previous post on that problem seems to be correct.

...do you think new vinyl washers could be made with sheet vinyl (a beach ball) and a stencil cutter (x-acto knife)?

albertj wrote:

...do you think new vinyl washers could be made with sheet vinyl (a beach ball) and a stencil cutter (x-acto knife)?

I would think so.  The washers are somewhere between 0.003-0.005 thick (as stated before, about as thick as a dollar bill). The material seems to stretch somewhat and deforms as the trunk hinge is removed from the trunk water channel.   If you can stretch the material you're considering a little bit but then it primarily goes back into shape with some slight permanent deformation, I would think you have a good substitute for the original material.  If you want NOS appearance, then choose a black beach ball.