Rep Power: 0

Hi, I have 2003 Civic EX. My husband uses it for his main car while I use the '06 odyssey.
Lately when I've been in the Civic I've smelt mildew (within the past 4 months). I went to clean it out for him yesterday - changed the cabin air filters, vacuum, etc and noticed mildew growing on the removable carpet on the front passenger side and a little on the right side of the back removable carpet. When I went to clean that up, I removed the carpets and noticed the front passenger floorboard carpet was SOAKED.
I pulled up the carpet in the front and saw water standing where your feet go and it was damp up under the glove box.

We've taken it to our local Honda dealer and they couldn't diagnose it. I'm taking it to a local glass shop that replaced the windshield about 7 or 8 years ago for a free water test to the windshield and the sunroof.

I appreciate all help anyone can give me! I really want to know where the water is coming from and just how much trouble it is to get all of the carpet up so I can lay it out to clean and dry it. Like do I have to remove the seats? Thanks everyone!

 
Rep Power: 208

if its not leaking in from the outside, you could have a coolant leak in your heater core, and/or connecting hoses, has your coolant level been going down?

 
Rep Power: 0

The inspection from Honda said:
"Found coolant excessively diluted"
and
"Found engine coolant leak"

So, maybe this is the problem? If so, how do we find out and how do we fix it? Thank you so much!!!

 
Rep Power: 209

The first thing I would do is determine if the moisture is water or coolant. If your nose is sensitive enough to detect mold I would think you would detect coolant. Most antifreeze has a sweet smell, kind of like maple syrup, as well as a sweet taste. If it is antifreeze the most likely source is the heater core which is difficult/expensive to replace. That is why I say you really want to be sure what the fluid is.

Besides leaking from a replaced windshield, another possibility is from the air conditioner. If the drain from the A/C is plugged it can dump water inside the car.

As far as removing the entire carpet for drying, it is probably more work than you would like. A simpler solution (but not as good) would be use a shop vac to extract all the water you can and place a small fan to help evaporate the rest. Removing the passenger seat and lifting that section of the carpet would help.

 
Rep Power: 517

Where did the dealer say the coolant leak is? (I'd think in the engine compartment, and that would be a completely separate problem.)
I've not seen one of these heater cores leak yet in my 10 years at this dealer.


I'd think AC evap case drain, windshield, door vapor barriers, body seams and sealer,
Sunroof drains! The tubes detach from the elbows to the exterior, up behind the kick panels.

Leak tests should show leaks. (You know there's a leak, keep checking until the source is found.)

No matter what, you need to get the carpet lifted up and fans on it to get it all dried out, above and below. This could mean stripping seats out of the interior, among other things.
That padding can hold a ton of water, and the water is probably in the rear half of the cabin too.

 
Rep Power: 0

The glass repair shop we took it to did the windshield and sunroof leak test and found it was the sunroof drain lines, they were clogged. They cleared the lines and tested for proper drainage and it's all good now.

Now there's the issue of the carpets and getting the mildew out. The water went back to the back seat floor board on the passenger side too. We were also told that there are stains on the ceiling from the sunroof drain lines. Sounds like a big job that a repair shop needs to take care of.

Thanks for all of your help!