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Water accumulating on rear floor of car

A couple of days ago, my wife noticed that the floor mat on the rear passenger side of her car was sopping wet. She thought perhaps a water bottle must have spilled or leaked, so she soaked up the water and dried out the mat. Today, the mat was wet again with about an inch of water accumulating only on the passenger side of the rear floor.

We have had no significant rain for more than two weeks; in fact, it’s been sunny and hot with temps in the 90s. There is no water on the front floor or the rear driver’s side floor. Due to the heat, we have run the AC, but it is working fine with no apparent leaks. There is no apparent leaking in the trunk or underneath the car. There are no apparent leaks from the radiator or hoses. Everything is working fine, except for the water on the rear passenger side floor. We can’t figure out the source of the water. Please help! Thanks.

The car is a 2006 4-door Toyota Camry LE with 199K miles on it.

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The AC extracts water from the air, so perhaps that is the source of the water. Usually the AC just dumps the water on the ground.

the following tutorial may help:

"Clean your AC drain if water is spilling into your car"

Usually AC leaks Result In Water On The Front Floor. Most Floor Pan Designs Keep The Water From Migrating To The Rear Floor. I Don’t Know Toyotas, But I’d Look Elsewhere For The Leak, First.

Edit: I reread the original question and see that it has not rained to contribute any water, so, if that’s the case, I would tend to agree with you, Bill. On my cars (not Toyota) the floor pan holds the water at each floor quadrant.

But what else could be a source of water? OP states it’s not rain water…

The next time the AC is used, and you stop somewhere, look under the vehicle behind the passenger side front tire. There should be water dripping onto the ground.

If you don’t see water dripping onto the ground, the evaporator condensate drain tube is plugged, and the water is running down the inside firewall, under the carpet into the back seat floor.

The drain tube can be cleared with compressed air.


My thought was no rain, look carefully where she park her car, it might be near grass and someone runs a watering system while she is at work. That would be weird, but the Brothers used to have puzzles like that.

Look in the spare tire well, oh yah. As well as the other places, Toyotas are known for that place filling up. If you do have water there, pull the drain plugs and leave them out.

Test for water leaks with a squirt bottle like dish detergent comes in. Don’t use dish soap. Car wash soapy water is best. Close windows and run AC full fan and squirt soapy water on window seams and trunk seal. If there is a leak, soap bubbling will be almost comical.

You sure it’s not raining overnight and you just don’t realize it?

Does this car have a sunroof or an antenna on the rear fender? If not, just get inside and run the hose on that side of the car. Some seal somewhere is leaking.



Yeah, it’s a longshot, but I might test it if the side soak didn’t reveal anything. Who knows - maybe water could dribble through the roof and down the side frame near a window?

Tester’s and others AC vent idea is a good guess. The only other thing I can think of is that it is actually rain water intrusion from weeks or months ago, and there’s enough left insde the passenger compartment that what’s left just migrates back to that spot, even when it’s mopped up there the day prior. If this theory is correct, eventually the OP should see a significant decrease in the amount if that area is mopped up daily and there’s no rain.

If OP determines the source is rain water, first suspect is the sun roof, if the car has one. Next would be anything like windows or light fixtures recently repaired on the exterior of the car.

WAG: Water is getting into the rear door and running into the footwell from the drain holes at the bottom of the door.

has anybody checked that ac condensation drain tube yet . . . ?!

has anybody checked that ac condensation drain tube yet . . . ?!
Yep. It's fine. ;)


Where’d you get that idea?

OP has not specifically answered our question as to whether the ac condensation drain tube is plugged or not

Respectfully, I think you’re making assumptions

Based on what, I don’t know

Respectfully, I think you're making assumptions
Nope, making a joke. Not a very good one, admittedly. :(



I have the same issue - but never used AC.

It rained several days ago - but the water keeps filling back up tho I have soaked it up 4 times now.
There’s no rain overnight.

However- I do have a level of water in my passenger tail light.

Did this original post ever get solved ??

I have a Subaru Impreza wagon

Ever resolved?? I have exact same issue - but never used AC. It rained several days ago tho. But after two days of soaking up water ( no rain during those days) it continues to be sopping wet.

If you can’t see a resolution in the posts, then the original poster (from 3 years ago) never posted back with the solution.

If it leaked during rain, you likely have a window seal gone bad or a rust through hole around the window frame. Or possibly a plugged sunroof drain. BTW, rainwater that gets inside, takes a long time to dry out.