A lot of water got in trunk somehow

[Muse]

Last winter and this, I'm seeing moisture in car, evidenced by very heavy clinging fog on inside of rear window of my Mazda 626LX 1997 4 cylinder automatic coupe with less than 30k. This car is always left outside in the elements on my driveway, there's no room for it in the garage.

I thought maybe it was because the replacement windshield done just before last winter had been installed incorrectly. A rock kicked up on freeway and cracked the windshield, and I had it replaced by a cut-rate outfit (compared to others). They sent a guy out who did the job at the end of the day when it was close to dark. By the time he was done it was dark. He was probably hurrying, wanted to get home to his family. It looks OK except that it wasn't really centered, it was off by I'd say at least 1/4 inch to one side. I took the car to a well rated (Yelp) one-man shop and the guy told me it shouldn't be a problem. However, that moisture inside the back windshield made me suspicious.

This winter I have had the same problem, here in rainy season. It doesn't freeze here. Well, around 2 weeks ago I noticed moisture hanging down from the bottom of the trunk lid and figured maybe the moisture was getting in the trunk, not the front windshield.

I removed everything from the trunk, including the spare tire and there was around 1.5 quarts of water pooled under where the spare was. I got that out, and removed the carpet-mat from the entire trunk, dried it out and on recommendation, dusted the trunk (in particular the vertical surfaces) with talcum powder and hosed down the car. But I couldn't see any indication that any water was getting in the trunk. The last day it's rained some, almost 1/2 inch, and I still can't see a drop of water getting into the trunk.

What can account for all that water having pooled under the spare tire??? I can't remember a water jug breaking or anything like that. A time or two I did leave a window cracked a bit open, probably one of the two back windows, by mistake during rainy weather, but even if a lot of water penetrated, how could that reach my trunk I don't understand.

Does anyone have an idea about this? Or should I just put the now-dry carpet-mat back in the trunk (after removing as much of that talcum powder as possible from the bare metal surfaces inside the trunk), and keep my fingers crossed?

 

[Muse]

Is it possible that all that water is from water kicking up from a wet road when driving in rainy conditions through some entry point(s) from below? I don't know how else that water could have gotten in there.

 

[sontakke]

Is it possible that all that water is from water kicking up from a wet road when driving in rainy conditions through some entry point(s) from below? I don't know how else that water could have gotten in there.

Certainly; look at the wheel wells. I had similar condition in an old Honda; drove me nuts for months until I figured it out.

 

[Muse]

Certainly; look at the wheel wells. I had similar condition in an old Honda; drove me nuts for months until I figured it out.

Thanks. I don't drive the car a lot of the time, that's why it's under 30k. Next time it's raining good I'll take it for a spin a bit and then check in the trunk. Right now I can access the trunk from the back seat because I have the back seats folded down. I go in there with a flashlight and have a good look at all the interior trunk surfaces without having to open the trunk lid.

 

[RLGL]

Try the tail lights, a Neon did that to me

 

[waffleironhead]

Have a spoiler? That was where my grand am leaked.

 

[Meghan54]

I'd also do a quick scan of the weather strip/seal for the trunk lid for a small tear or other defect that could allow water to get by it.

 

[sontakke]

Get a sprayer on garden hose and wet the entire car from the top aka simulate rain. Then check in the trunk. If no water, spray upward from wheel wells. If you find water, you know for sure it is coming from there.

Also as somebody else responded, tail lamp gaskets can dry out and let the water in. I had this problem too on the older Honda. The car was too old to get the new gaskets, so I used silicon goop to seal them.

 

[Pacfanweb]

Out of the thousands and thousands of water leaks I've repaired, tail lights are a big culprit for trunk leaks. They aren't hard to duplicate, though. You do need to pull the interior panels or fabric out to see where it's entering.

If it got wet from just sitting, that eliminates a wheelhouse leak from the tires spraying water while driving.

If it WAS a wheelhouse leak, you should see a very dirty place where the water and dirt came in...the water dries up and leaves the dirt behind. It's a dead giveaway. That's what I always look for.

Another possibility is someone bumped you in a parking lot. Happens all the time, and many times doesn't leave any mark on the bumper. When the bumper shocks flex, sometimes they flex the rear sheet metal and split a seam.

Of course there's always the possibility of the trunk seal itself, but these are rare. Sometimes water can get under the seal, though, and travel over and enter at the bottom of the opening. Pull up the plastic piece that is at the bottom of the opening and see if there's water stains there. I usually clean the seal and then seal it down when this is the case, unless the seal is in bad shape...then I get a new one and seal IT down.

Does it have a sunroof? If so, the rear drain tubes can be clogged or disconnected...they usually run down the back C pillars and into the trunk and connect to the exit spouts on either side. If they're clogged, that can do it, too. And unless you specifically test them, you likely won't get them to leak by just hosing the whole care. They probably only leak on a long, steady rain.

I will post more if anything else comes to mind.

 

[gururu2]

Does it have a sunroof? If so, the rear drain tubes can be clogged or disconnected...they usually run down the back C pillars and into the trunk and connect to the exit spouts on either side. If they're clogged, that can do it, too. And unless you specifically test them, you likely won't get them to leak by just hosing the whole care. They probably only leak on a long, steady rain.

I will post more if anything else comes to mind.

One of my tubes and pulled out and was leaking water into the trunk spare tire well like crazy. Took me months to figure it out.

 

[Muse]

Get a sprayer on garden hose and wet the entire car from the top aka simulate rain. Then check in the trunk. If no water, spray upward from wheel wells. If you find water, you know for sure it is coming from there.

Also as somebody else responded, tail lamp gaskets can dry out and let the water in. I had this problem too on the older Honda. The car was too old to get the new gaskets, so I used silicon goop to seal them.

No sunroof on this car. No spoiler, either.

If it got wet from just sitting, that eliminates a wheelhouse leak from the tires spraying water while driving.

The car sits a lot but I don't know if it got wet from just sitting outside, have no idea if it did.

I simulated rain a couple of times with garden hose and high pressure nozzle a few days ago. Not a drop could be found after that in the trunk.

It was supposed to rain today, but we have only gotten an afternoon drizzle. It's enough to get the roads wet, even create a few puddles. I just took the car for a total ~5 mile ride to a supermarket in this drizzle. Again, I don't see a drop in the trunk. There's talcum powder everywhere and there's no hint of a dribble trail. Maybe if it really rained a decent clip and I drove in that, I'd see some water entering the trunk, I just don't know.

I could try what was recommended in this thread, being to shoot water into the wheel well from below with a nozzle on garden hose. Since no real rain is forecast here for a while, I suppose I should try that. Just shoot water up from under the fender around the wheel?

If it starts raining harder, I'll get in the car and drive it for a while and see, but the report calls for the little rain we're getting going completely away in an hour or two and nothing in the days ahead.

At the very back of the trunk, just outside the rubber surrounding seal there's a trail of dried muddy water. But that's outside. I see where it would go into cracks, and I theorized that water might have gone into those cracks and found its way into the trunk, but pouring some water into those cracks didn't cause any to appear into where I saw it pooled last week (under where the spare tire goes).

If the leak is at tail lights I'd think my gunning the whole car with nozzeled hose for 8 minutes would have made some water get in there. I didn't spare the tail lights.

I've pulled out pretty much everything from the trunk. There's a big ~5' x 7' carpet-mat affair that attaches with plastic fittings and (I think) a little velcro. I pulled out all those plastic fittings and put them aside and let the carpet-mat dry out by placing it in the sun (such as there is this time of year) over around 3 days. There are several ~1" thick pieces of evidently fiberglass matting that's attached to the underside of the carpet-mat, and that's where most of the wetness was, tool the longest to dry. It's all virtually dry now, but it's sitting in the garage. The interior of the trunk is all painted metal now, covered with a thin layer of talcum to show any water movement. There are two compressed wood affairs at either side at the back of the trunk that kind of attach to the bottom of the carpet-mat. They have ~3" long triangular plastic stays that reach down into depressions at either side below the thin compressed wood, I guess the function of this stuff is to support the portions of the carpet-mat that are above them. One of those was completely rotted out and I removed the pieces it had decomposed into. The other one (at the left rear of the trunk), seems like it's pretty OK still. I don't think they are critical, and I'll just put the carpet-mat back in with one of them gone when the time comes. Meantime I'd like to find the leak but am beginning to think I might not find one!

I have a very old but unopened caulking gun tube of Ace clear silicone, also a new 11 oz. spray can of Rust-o-leum LeakSeal flexible rubber coating I picked up last week in anticipation of fixing the leak. But so far I have no idea where I would want to apply any of that stuff.

 

[Muse]

It started raining a bit harder and I took the car out for another ride of a few miles. Wanted to hit the freeway but it was jammed both directions, so stayed on side streets and thoroughfares. There's a small amount of water in there, barely enough to reach the bottom of the well that is under where the spare goes. Seems like maybe a couple of teaspoons of water got in. The trail shown by the talcum powder shows it's coming in from the back vertical surface of the trunk lid. I don't know where it's penetrating, the surface of the trunk lid has a lot of stuff going on. It might be coming in at the rubber gasket that goes all around the trunk 360. Might not have much to go on until there's a real rainstorm. Or I could try the hose again, but I kind of think that driving had something to do with it, but I don't know what.

 

[Pacfanweb]

Can you get a pic of the powder and the trail the water left in it?

 

[Muse]

Can you get a pic of the powder and the trail the water left in it?

You see the thin trail here going toward (but not reaching) the low-point of the trunk interior. Looking carefully, you can see a trail on the vertical surface in the back (which is the trunk lid), that vertical trail is about 2 inches to the right of where the trail on the trunk bottom is seen.

Maybe I can come up with something using a garden hose, couldn't before. No rain is expected until the first 5 days of March, which are projected for showers with a maximum of 60% chance at this point in time. Meantime I have no use of the trunk and the back seat is folded down so I can see in the trunk. I have a bunch of stuff that's normally in the car in the house.

 

[boomerang]

Can't see your pic.

I would quit waiting for rain, etc., and start exploring. Take a very close look at the weatherstripping surrounding the opening. Flex it and tug on it lightly, etc. If that's the cause of the leak, you'll find it. If you still suspect it, smear vegetable oil on the sealing surface on the deck lid itself, carefully close it and latch it, open it and see if it transferred. You should obviously have a continuous transfer around the circumference of the weatherstrip. If not, replace it.

If the picture of your car I found is correct, you have either tail lamps or reflectors mounted on the vertical surface of the deck lid. Those may be retained with plastic wing nuts that can be removed by hand or may require tools. I would take a look at the sealing around those mounting holes. Also, where the wire harness comes through for the license plate lamp and/or any wiring for those tail lamp/reflectors should that apply.

Without seeing the pic, some or all of the above advice may be way off base. From your description it sounds like it's leaking where something (fasteners or wiring) is penetrating the vertical surface of the deck lid.

 

[C1]

Ive had something like that happen to me (ie, trunk water leak).

A likely possibility is a break in the body seam in the trough surrounding the trunk (that is under the trunk lid). You should be able to test this using a garden hose. By now you'll probably even notice some rust beginning on the under side of the trough (look up from inside the trunk).

Such leaks are easy to repair using standard auto body stick caulk.

 

[Pacfanweb]

Can't see the pic, either.

 

[Muse]

Can't see the pic, either.

In the previous post I pasted this in using the URL icon here. Works for me, maybe you can paste it in as your browser URL:

https://lh3.googleusercontent.com/U...SRRMS2-5NNAUeuTki3stE6gvrQvHq4k=w1574-h884-no

It's in one of my Google Photos albums.

 

[Pacfanweb]

In the previous post I pasted this in using the URL icon here. Works for me, maybe you can paste it in as your browser URL:

https://lh3.googleusercontent.com/U...SRRMS2-5NNAUeuTki3stE6gvrQvHq4k=w1574-h884-no

It's in one of my Google Photos albums.

Okay, I see it.

That's definitely your leak.
If that's the closed trunk lid above the leak, then your leak is either from behind the rear bumper, (probably a split seam) or possibly still from water going "up and over" inside the trunk gasket. I'd have to see how the car was made outside that area to be sure.

You should be able to pour some water at the gap between the trunk lid and the bumper and reproduce that leak if it's behind the bumper. If that's the case, it may well have been bumped in a parking lot and split the seam. Would be an easy fix, but getting to it may or may not be easy.

If it's water traveling underneath the trunk seal, I think I already told you how to fix that. Just based on that pic, I'd get a flashlight and see if I could see inside one of those holes and see if the water's coming in right there or somewhere else and that's just where it enters the car.

There are multiple possibilities.

 

[LTC8K6]

I see two trails running down and joining up to run into the spare tire well, I think?

 

[Muse]

I see two trails running down and joining up to run into the spare tire well, I think?

You're right! I didn't notice the one on the right.

 

[Pacfanweb]

What is the green part? That's not the inside of the trunk lid?

 

[Muse]

What is the green part? That's not the inside of the trunk lid?

I can't see any "green part." I am totally green blind.

However, I suppose anything you see there that's green is the car or talcum. I took that shot from inside the trunk with the lid closed using my EDC flashlight and smartphone. The car, they tell me, is painted green, so I suppose it's the paint that's green.

I'd really like to fix the problem soon. I have a bunch of stuff cluttering up the house that goes in the car ordinarily. It may rain a bit come Saturday, may not. Meantime it's dry. I could try sealing some things now and hope. I could make more tests using garden hose. Of course, I would want to let that stuff dry out before trying to seal, an additional complication. I'm going to try to inspect what's going on today, see if I can at least postulate where the water is entering.

 

[Muse]

Looking today from outside the car with trunk lid up I spotted 2 more leak points. The water trails come from what appear to be bolt attachment points from the left tail light. They appear to drain into a well behind the left wheel, not where the water pooled under the spare. I suspect that water has been getting through the gasket interface with the trunk lid. Don't know for sure, but there's absolutely evidence that water has gotten on the other side of the gasket (the gasket seat on steel flange is quite wet) and there's telltale track of muddy water on the in-side of the gasket. That doesn't prove that the water got through the gasket seal, might have gotten there some other way, but the gasket seal is suspect.

I figure I'll use clear silicone on the tail light bolts. Don't know how to deal with the gasket other than replacing it. That's what I'd need to do for the gasket, right? I could try Boomerang's idea of vegetable oil on the gasket surface and see if it makes contact all around. Then wipe off the vegetable oil, I suppose, with a rag.

 

[Pacfanweb]

In the pic where the arrows are...where the 4 arrows are close together, it's green there. What part of the car is that? Is that the inside of the trunk lid, or the quarter panel?