Mildew Smell and water buildup in door after rain

Hello all, this is my first post in the forum. I wish the circumstances were positive rather than negative, but these were the cards I was dealt.

About 55 weeks ago I got my brand new 2022 Toyota Tacoma Off-Road. Everything has been great since up until a few months ago.

Less than 2 months ago I started smelling mildew in my car and I didn’t think much of it so I masked it with an air freshener. It gradually got worse to the point that I could not handle it anymore so I decided to look into it more.

I noticed that the smell is much more potent after rain, which we got a lot of here in NJ/NY this past summer/fall. The smell would smack my nose every time I opened the car door, giving me a headache. Another thing I noticed is that after it rains and I open my driver side door, water seeps from the top like a mini waterfall (may be over exaggerating a little bit here). It doesn’t necessarily get on the carpet or in the car, but it gets all over me when I get in the car.

I searched my entire car. Began reading through the forums. I got a little paranoid because I started reading about the risks of leaks through incorrectly installed roof-racks. I had just installed a Prinsu Roof Rack 4 months ago, even thought I was very generous with a bottle of silicon during the install. So I began checking the roof after it rains, handles, essentially everything in my car. After a few big storms, I checked my car and found nothing wet. I began to strip my seat covers, remove my seats and do a deep search.

This is what I found. A very minor area (3in X 3in) in the back passenger side with mildew (photo attached) under the seat towards the corner, adjacent to the bed.

What I also noticed is what I believe is the culprit. On every single door, the seal strip looks sloppy. There is mildew growing on the seal strips/gaskets. And looks like a water line (brown) along the top. There is even a part of the seal strip that looks like it’s about to fall off. The passenger side looks worse than the driver side.

Has anyone seen similar issues to this? Thank you for reading.

 

My bet is your roof rack is leaking. Those seal look typical like that all I've seen. Silicone is not a great sealant to use when installing roof rack. Butyl or gutter/flashing sealant.

 

I’ll definitely investigate the roof rack situation some more. The only thing I question is that there is no signs of water inside the car, on the roof, floor or on the seats after it rains.

I attached more photos of the door seals. I never realized how sloppy they look.

 

I would say take it to your dealer to see if your warranty might cover this, but they will most likely blame it on your aftermarket roof rack install.

 

Your seals are fine, the rack is most likely the issue

 

So I found the source…

Underneath my dry weather tech mats, the carpet was little wet, and beneath that the insulation/padding was soaked. I took it out and squeezed the water out like a pool towel.

This was the carpet at the front driver seat. There was a small portion on the passenger side with moist insulation as well, but not nearly as much as the driver side.

I am mind blown that if the roof rack was the cause, that there was absolutely no sign of seepage through the roof or drips on the seat.

I began the roof rack uninstall, and there wasn’t much sign of water seepage through the factory threaded hole, so I guess I will never know. Regardless I have began preparing for a LIFE PROOF roof rack install.

Does this still sound like a cause of a improper roof rack install?

 

It's most likely running down pillars A, B, &C pillars. Silicone is no-good, loses its bond.

 

Does this still sound like a cause of a improper roof rack install?

Yes. Since thats what everyone has suggested

 

put some paper or something around the upper part of the foot wells where all that water is pooling, close your doors, and run your hose over the roof of the car. see where the paper is getting wet. trace it back up.

it's still probably the roof rack. hard to think the drain plugs under the insulation stuff is missing

 

Or by sheer coincidence, your sunroof drain hoses have dislodged from the sunroof tray. That is if you have a sunroof.

 

The roof rack leak would not be covered since it was installed third party, so I began removing it and will reinstall with a liberal amount of waterproof sealant.

Luckily my car is under warrantee for another year or so. I will check for additional leaks going forward, at this point I will absolutely know that any future leak would not be from my roof rack.

I appreciate all of the input. Now I am working on drying the inside of my car and properly installing the roof rack. Thank you.

 

No sunroof fortunately and unfortunately.

 

Roof rack leaking not covered by warranty, regardless who installed it. Ask me how I know. If your front driver bolt was leaking it would be running down your A pillar and directly into your PCM, again ask me how I know.

 

I have the same issue on mine. I agree, its the roof rack. I was going to pull the hardware and put thread tape on it and also push some sealant in.

 

Sounds like it's time to reinstall/reseal my Prinsu. We had the first hard rain in ages and passenger floorboard was flooded. Thanks for the heads up!

 

I had a similar issue. I never developed mold, but my bed lights started glitching on and off after heavy rains. I noticed the relay that controls the bed lights (under the driver dashboard close to the fuse box) has a little bit of water on it and I traced it up the A-frame to the top of the door. I had thought the same thing about my roof rack (Cali Raised) since I read (probably) the same posts you did on TacomaWorld. I never sealed my roof rack bolts with loctite so I thought that was the issue. So I tested that theory by pouring a bottle of water over those roof rack holes, but no water entered the A-Frame. However, when I then pour water right on top of the A-frame where the front windshield top meets the frame, I then saw water entering the inside gasket of the door. I thought this might be a warranty issue since my 2020 was only a couple years old, but I have done so many modification and have wiring running up the outside edge of the windshield for lights that I 1) figured most dealers are going to make that an issue and 2) I did not want to have to redo my wiring. So I took the solution into my own hands, bought some l

$10 Loctite Clear Silicone Sealant, 2.7 fl oz, 1 Pack - 100% Waterproof Sealant for Glass, Ceramic, Wood, Plastic & More

octite clear silicone and put a dab right were the windshield meets the frame. That fixed the issue for me and I haven't seen more water ingressing in heavy rains. I'd recommend doing the same water pour test just to make sure you located the origin of the leak.

 

If you’re sensitive to mold I suggest you ditch that piece of jute insulation under that rug, replace it once you know the problem is rectified.

 

I threw some thread tape on the affected hardware yesterday and it’s already made a difference! Oh and it hasn’t stopped raining.

 

Thought I’d give an update…

So I ripped out and replaced the insulation under the driver and passenger seat carpet (only affected area). The driver carpet smelt like mildew, but after spraying mold remover and a deep clean, the smell was faint.

I completely removed the Prisnu roof rack and cut the weather stripping into pieces, rather than making a hole in it for the bolts (ensures a better alignment). I siliconed the inside of the hole, reinstalled the roof rack, let everything dry, then did 2 rounds of siliconing (allowed to dry between). Then I installed some butyl tape at the bolt heads/roof rack connection to prevent water from running in through the top.

10 months later… the mildew smell completely went away after a decent amount of odor eliminator sprays and nice day windows open air outs.

I appreciate all of your feedback in helping me solve this issue.

Note to others thinking about installing a roof rack on your truck… take the extra time to do it extra right to save yourself a lot of time and headache in the long run.