Water under carpets, NOT A/C.

Asked by GuruVDCH9 Aug 02, 2018 at 09:25 PM about the 2008 Toyota Highlander Base 4WD

Question type: Maintenance & Repair

Hi, have had wet carpets front and back for a while now.  Initially thought it was A/C as did mechanic, but it is not (drain tube works fine).  I finally removed carpet to the back seat row to expose bare floor.  When sitting level and not driving, even in heavy rain, water does not enter.  So I drove the vehicle in a pouring rain and whenever I braked, water was seen oozing from the side floor body wall BEHIND the driver's, and to a lesser extent, the passenger seat as well.  I removed the floor side plastic trim at the entrance to the back seat row on both sides.  When I injected water into the holes in the frame that the molding fit into, with the car FLAT, level and parked, it just drained out the bottom.  
BUT, when I put the car into a downward facing slant, with ramps under the back tires and do the same, I reproduce the leakage into the passenger compartment in exactly the same place as seen when driving.  So it looks like the water enters under the floor molding, from around the back door and runs forward in the frame when the car slopes forward or is braking.  I plan to silicone around the attachment holes for the trim and see if that fixes it.  Any other ideas?  Thanks, James

34 Answers

160

Hi, I have the same problems when it rains, without moving the car, the rear seat carpet gets water, I have put new plugs on holes inside the bumper (2 were missing), today with the first rain, the car parked, I noticed water again in the same place, my sunroof drain holes, all 4 drains when I pour water on them, also the A/C drain hose, drains a lot when the A/C is working, I remove the column plastic cover and on the side of the seats, front and rear and all looks dry after the rain. Any hints?

16 people found this helpful.
440

I have a 2013 Limited Highlander, just paid the dealer $900 to "fix" this. It turns out the sunroof drains "somehow" drain into the floorboards and not out of the car--when the drain tubes are clogged. I'm not sure what idiot at Toyota designed this. Now I have to use my air compressor to blow out the tubes from time to time so this doesn't recur. Btw today I was in a Toyota shuttle to pickup my car, and the other person had the same problem, same model. I need to find out if there is a Toyota service bulletin that covers this. Also, my stereo/radio was damaged because the amplifiers are in the floorboards. Still need to get an estimate to fix that. Not sure if the in-dash original stereo survived.

44 people found this helpful.
710

after reading all of the blogs on this I finally figured out how to fix it. should only take 30 mins once you know how to do it. Note- this is for highlanders that get wet floorboards after rain. not the A/C issue. you can test by running a hose on top of the sunroof. if the mats get wet - the below is the solution 1 - remove the plastic trim covers that are on the side of the floorboard that are closest to the outside of the car (eg on the drivers side this is the cover closest to your left foot). there is a small black plastic nut you need to unscrew (mine came off with my hand). then the rest of it just pops off (one clip at a time) if you feel around and pull reasonably hard. dont need any special tools 2 - you will also probably need to remove the plastic cover that is between the side of the seat and the outside of the car - it rests on top of the cover described above so 3 - remove the plastic wire boxes clipped to the side of the car - under the covers removed in step 1. just pull hard. that will reveal a hole 4 - if you want to test the issue: run a hose on top of the car near the sunroof. assuming the sunroof drains are not clogged (if they are run some stiff wire down them) - the water will come spilling out of the holes you just exposed when you took the plastic wire boxes off 5 - blow an air gun with a long nozzle into the hole and point it toward the back of the car. might be best to do this while the water is running to increase the pressure. the goal is to blow the blockage out from the "pinch welds" that run from the front wheel well to the back under the car. keep moving the air gun around until you get good flow coming out from under the car. if you dont have an air gun (i didnt) find a mechanic (eg at a tires plus) and ask if they will help you sometime when they get slow. offer to pay cash ;) 6 - you will know if it worked when water starts draining much faster from those pinch welds. you should now be able to leave the hose running on top of the sunroof without having water come out of the exposed hole 7 - dry everything out. i ran a leaf blower under the carpet on each side for a few hours 8 - put it back together

47 people found this helpful.
1,130

In response to Dave and his air method. Bought a 2010 highlander with soaking wet floorboards ( didn’t notice it with the weatherproof floor mats until I cleaned it and saw they were soaked). I tried blowing air with compressor but it didn’t work for me. I had to unplug the wires and pull the box out to access the drains. I rigged my shop vac and sucked up as much debris as I could. Then used a wire to dig around the drain and vacuumed up again. Poured vinegar to rinse out. Ran the water hose on the sunroof for a while and now water drains underneath the car through the pinch welds as is supposed to. Check out my photos.

22 people found this helpful.
130

Michael and Dave—this was so helpful what you both posted. No way I could have figured this out on my own. I ended up jamming a chopstick down the small hole a few times and finally got the funk through for water to flow. Did pour in a vinegar solution to help clean out afterwards. Thanks again.

13 people found this helpful.
1,130

Hey guru glad it helped you. I searched and searched for solutions too. Finally got it. I hope yours and mine hold up for a while!

7 people found this helpful.
60

thank you so much for this information! My 2011 Highlander was soaked and this wasn't the first time. We used a Kabob skewer and an air hose. It was pretty clogged and took a few tries. we aimed the car front down and ran the hose over the sunroof. I can't thank you all enough for this. I'm sure you saved me a ton of money.

6 people found this helpful.
40

I’ve been noticing a wet spot forming in rear passenger ROOF. Thought I had maybe left the sunroof open one day but it’s getting worse every time it rains. Today, I noticed the seat belt was Soaked. Floor boards are not wet..... anyone know what this problem could be?

4 people found this helpful.
110

@Michael- where exactly are these drains? I can't seem to picture where to look for them based on your picture. Are they inside the front quarterpanels? Or are they under the floormats?

11 people found this helpful.
120

Just to add to the fun... My wife has a 2008 Highlander Base, no sunroof, no third row. After a couple days of rain the smell of mildew was unbearable. I removed the rubber floor mats to find the entire floor was wet, front and second row. I read these posts and many others (thank you, all) to see what cause could be. I ran the hose all over the roof but it wasn’t the front column clog. It wasn’t coming through the side columns. So I decided to remove the rear storage unit (in models without third row) and found two pools of water near both wheel wells. So apparently water was entering somewhere in the back and making its way forward when the brakes were pressed or when it was parked on an incline. I removed the bumper and saw all the rubber plugs were in place. So I ran the hose (slowly) with the rear door open to see if there were any obvious entry points. Nothing stood out so I just sealed a few holes that didn’t seem to have a purpose. I also resealed the weatherstripping. This seems to have fixed the leak from the right rear area. Unfortunately, there’s still a slow leak from the left rear (see photo). Not sure what to do at this point. Any suggestions would be appreciated. I hope this helps someone else find their highlander water problem.

9 people found this helpful.
120

Where the leaks were on both sides of the vehicle (still leaking on the left side)

1 people found this helpful.
50

I have a question. I think this is happening to me and my 2010 hghlander. The floor boards are getting wet on the door sides. What do I need to take off to remove or check the lines for drainage. Sorry I feel a little overwhelmed. I appreciate any help you could assist me with. My email is carr.caleb85@gmail.com if you would like to give me a little more instruction. Thank you in advance!

5 people found this helpful.
10

I, too, have water on front passenger floor in my '05 Highlander. A stopped up drain sounds reasonable, but am not mechanically inclined and totally green when it comes to figuring out exactly what your instructions are, Dave and Michael. Don't have an air compressor... New front bumper was recently installed, but can't figure how that would be the culprit.... Would deeply appreciate greater detail, if you can. Help!! My email address is longmillie@aol.com. Thank you soooo much!!

1 people found this helpful.
710

Best would be to do the mechanic / cash thing I suggested. Especially if you aren’t comfortable taking th covers off You could try using a chopstick or hanger and jamming it around (good to do this while someone else is running the hose on the sunroof so you know if / when it’s cleared. The water will start pouring out from under the cart when it’s cleared. The mats are going f to get even more wet until you clog it but that’s ok.). Could also start by dumping drano some drano down the hole (need a funnel). Not sure if that will work but worth a try - would be much easier than chopstick / hanger / airgun etc Either way you need to get the covers / electrical box off first

1 people found this helpful.
105

I have a 2012 Highlander Limited and the passenger rear carpet gets wet after a rain. Does anyone know how many drain holes are in the sunroof? Thanks in advance.

10 people found this helpful.
110

I have a 2007 Highlander which fills with rain on the passenger side. Since I rarely use the sun roof, I bought a 2'x5' piece of car wrap for about $12.00 and put it over the entire sun roof. I does not peel off at highway speeds and I no longer have any rain problems

11 people found this helpful.
50

Outstanding help!!! If it is the clogged down in the frame part and coming out the holes inside through sidewall. You can go underneath the car and with a small chisel just open the drain slots wider and it will drain as needed.

5 people found this helpful.
50

2013 Highlander - I am so glad I found this post. I had looked everywhere. Thank you so much!!! While this was not a fun job, especially pulling out the wire boxes, but it saved me a lot of money. As an engineer, I cannot believe that Toyota would design something like this. I hope my 2021 Highlander never develops the same problem!!!

4 people found this helpful.
10

Hi guru I have a 2013 with water coming in also on my drivers side. It’s not my AC line like it was once before that made water go on my passenger side. I had another water issue with clogged sunroof drains making my roof and belt wet. But not my drivers side floor issue I can not solve where the leak is. The picture you posted where is this small drain? I can not find it under my carpet. Is it on the left drivers side quarter panel behind all the wires?

1 people found this helpful.
60

Guru96M5J4 - you have to unplug the wires and then remove the wire box. You won’t be able to see the drain - all the photos posted are from a phone inserted into the cutout where the wirebox goes. I used a kebab skewer, brillo pad and drano. Then flushed with very hot water. So glad to be getting rid of the stink!

5 people found this helpful.
60

After cleaning - our drain pan is black instead of white. Initially thought my scrubbing wasn’t making any difference.

1 people found this helpful.

Intrestineg to read all of this. We are looking at getting a Highlander after having water leak issues with Rav 4 and no sunroof. Im thinking that Toyota have used same basic flawed design principles for both, and now the class action for the roof rail issues. Not good Toyota. Are any years more prone than others?

Your Answer:

Highlander

Looking for a Used Highlander in your area?

CarGurus has 17,781 nationwide Highlander listings starting at $2,900.

ZIP:

Own this car?

Share your experience with others.

2008 Toyota Highlander

Review another car

CarGurus Experts

  • #1
    Wendy Tucker
    Reputation
    6,430
  • #2
    Stillsearching
    Reputation
    3,660
  • #3
    SIdd
    Reputation
    3,080
View All

Know more, shop wisely

Search

Related Models For Sale

Used Honda Pilot
830 Great Deals out of 27,913 listings starting at $1,950
Used Toyota RAV4
1,788 Great Deals out of 29,710 listings starting at $2,495
Used Toyota 4Runner
1,008 Great Deals out of 20,368 listings starting at $1,950
Used Toyota Highlander Hybrid
173 Great Deals out of 2,794 listings starting at $4,000
Used Lexus RX
798 Great Deals out of 14,251 listings starting at $900
Used Acura MDX
551 Great Deals out of 15,318 listings starting at $1,200
Used Toyota Sienna
590 Great Deals out of 9,174 listings starting at $1,995
Used Toyota Camry
2,022 Great Deals out of 40,475 listings starting at $1,550
Used Honda CR-V
1,928 Great Deals out of 40,647 listings starting at $1,200
Used Toyota Tacoma
1,574 Great Deals out of 26,753 listings starting at $3,700
Used Toyota Sequoia
144 Great Deals out of 3,484 listings starting at $3,500
Used Ford Explorer
2,117 Great Deals out of 61,560 listings starting at $900
Used Toyota Tundra
1,004 Great Deals out of 31,596 listings starting at $2,922
Used Lexus GX
256 Great Deals out of 3,180 listings starting at $3,950

Used Cars for Sale

2024 Toyota Highlander For Sale
3 Great Deals out of 5,064 listings starting at $29,917
2023 Toyota Highlander For Sale
112 Great Deals out of 1,874 listings starting at $26,475
2022 Toyota Highlander For Sale
86 Great Deals out of 1,095 listings starting at $24,900
2021 Toyota Highlander For Sale
192 Great Deals out of 2,738 listings starting at $19,999
2020 Toyota Highlander For Sale
78 Great Deals out of 870 listings starting at $18,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.