After that heavy rain 2 days ago, my wife found 2" of water on the passenger floor of my daughter's 2012 CX9.

Last year, we had a blower motor fail and that was caused by water, so I cleaned out the A/C drain line under the car and replaced the blower.

We never had water in the car before. The ONLY place that is wet is the carpet. Doors, seats, dash, and roof header are all dry.

Last time we went through car wash, no leaks. Car hasn't been driven this week. Just parked with windows rolled up.

This situation started July 6, and we dried it out that day. But it happened again this week after a heavy rain.

 

Time to get a small person with a flash light that can wedge themselves under the dash while with all the windows up another person hoses down the vent area.

 

I took off the windshield wipers, removed the plastic cowling and inspected. It's bone dry in there. Then I filled that trough with water from the hose. Saw water running out under the wheel well. Nothing in the dash/floor area. Puzzling.

 

If you have a sunroof in the car, it very well may be that the drain hoses are clogged and backing up. Test the drains within the sunroof.

 

Thats a good answer ^^^-
especially for those that drive in the rain or snow with there sunroof opened.

-and should be check and at least cleaned with low pressure air and 50/50 isopropanol alcohol. The lower drain tubes drain the water out the wheel well. If the hoses are not damaged, disconnected or the plastic hose adapters are intact water does not drain into the cabin area.

The drain hole when the sunroof is closed are not exposed to water.

 

Wouldn't the ceiling header be soaking wet if the sunroof were leaking (I had this on my '89 Mitsu Gallant)? The ceiling is bone dry. And the sunroof was closed at all times. She never opens it.

 

then the leak is not from the sunroof…


I just read your first post again. Were you exaggerating a little about the depth? Two inches ,is a large depth and that kind of water accumulation would be easy to find.

Normal hard to find water collection on the floorboards is more like wet carpets but not anywhere near 2 inches.
Guessing but to collect 2 inches of water it would take almost 3.5 gallons of water if I did my volume math correctly. Lol

 

No exaggeration at all. I could literally see a reflection off the pool of water in the floor pan and the back floor carpet was wet this time. We sucked out 2-3 gallons of water in a shop vac yesterday. My wife and I had to lift the shop vac, it was so heavy after vacuuming out the water!

 

Ok well leak that large should realistically be easy to find!
Perhaps you best recommendation is to take it to a auto body shop that deals in collision which not saying your Mazda was in but the leak you are describing they would have the experience to know exactly where to look.
2-3 gallon is like leaving a couple windows down in an average rainstorm (non funnel effect) for hours.

Good Luck finding to water leak. Please post what was in the end found. Who knows it may be something new?