2003 camry sloshing sound in dash in front of driver-possible drain in front of windshield plugged?

The drain pan is under the evaporator. The noise you can hear is air in your coolant system trying to get through the heater matrix. Water doesn't slosh when you are stationary and just started the car.

https://www.fixya.com/cars/r29872074-vehicle_cooling_system_no_heat

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possibly is
at the bottom of the windscreen there is a plenum chamber that collects the water from the screen and drains it out via a tube either side into the front wheel wells
these drains can block up from leaves , dirt or rust and that will then retain water in the chamber giving you the sloshing noise as you drive
the chanber is where you normally get fresh air into the vehicle when you open up the fresh air control

Sound of sloshing water coming from behind dashboard - GM Inside ...

www.gminsidenews.com/.../sound-sloshing-water-coming-behind-dashb...

Nov 16, 2008 - 11 posts - ‎9 authors
Hey guys, I have a 1999 Olds Intrigue (3.8) with 137000 miles. ... However, the sound goes away completely as the car starts to warm up (after about 10 .... If you hear thesloshing on the drivers side of the dash, it is not the lack of coolent. ... Your heater core is leaking (passenger side sloshing, low coolant).

what the heck? Where's this water noise coming from??? - Car ...

www.automotiveforums.com > ... > Toyota > 4Runner/GX470

It sounds like water is sloshing around towards the engine compartment. ... is gurgling behind my dash. i figure as long as nothing goes wrong, i can just turn my stereo up louder to cover it up. ... I had the same problem on my Oldsmobile Bravada.... This may only happen when the vehicle is low on coolant due to draining ...Missing: 97

Sloshing sound behind dashboard - Discussion on Topix

www.topix.com > Toyota Camry

Are you certain it is rain water? It could be condensation from the A/C coil that fails to drain out of the drain pan, or possibly coolant from a leaking heater core. If you are certain it is rain water, depending upon the age of the vehicle, and possibly some other things, here are the possible options:

1. Leaking door gasket.
2. Leaking windshield seal due to rust
3. Leaking windshield seal due to improper installation
4. Leaking windshield seal due to acoustic (sound) over pressure (if you have extreme sound system with heavy bass)
5. If you have a sunroof, if the drain hose comes down the passenger side door column, it could be leaking into the passenger compartment rather than drain through the floor pan.

Have you had your windshield replaced recently?

It sounds like a heater core going bad, ac works good, do you have any of these symptoms, sweet musky smell, wet floorboard, frosting over windshield when defroster is on, adding water to the cooling system in your car for no apparent reason,

The drain for your A/C may be clogged causing the water to accumulate. You should be able to locate the drain from under the vehicle on the pasenger side, perhaps there is an accumulation of debri such as leaves for example. Also, sunroof drain may also be blocked. I can say I have seen this problem before, and its a good place to start. Good luck

i would check water in radiator as sounds like the heater box under the dash is leaking and will certainly end up on floor

may be your heater core

Thank you for allowing me to assist you with your issue.

Since you have described that there was a buildup of leaves under your hood, my experience here indicates that the "cowl drains" are also plugged up with debris. The "cowl" is where the air enters the heater box intake (this is the area under the hood, in front of the windshield, with a black screen-looking thingy under the wipers). Since air has to get in here, water & debris can also get in. There are drain areas on both sides of the cowl (in the corners) to eliminate water from building up in the cowl area. Try this: Take a bucket of water, and dump it under the windshield area where the screen is on the cowl panel. Look behind each of the front tires for water draining onto the ground. You should see a very steady stream of water on both sides. If not, you may have to take a garden hose & spray vigorously until the debris is carried thru. You could also take off the wipers and the plastic cowl panel for easier access to the corners where the drains are blocked. In any case, a large volume of water will usually make its way thru the blockage. This will cure your issue. Please repost if you have any further questions, or need additional assistance; glad to be of service to you.