Water sloshing around somewhere
 

I washed the car, including the wheel wells, and now I hear water sloshing around through the air vents when I start up the car, accelerate from a stop and decelerate to a stop.

Any ideas where the water could be? It's NOT the gasoline -- that's another sound altogether.

sorry, cant think of anything besides gasoline...unless you had your windows down and water got into your little holder on the sides of the doors?

That's odd. tell us if you find it.

The water probably got into the plastic tank-like areas in the duct work. There could be two - one around the A/C evap, and one underneath where the air enters the car from the outside. If there are areas where water could collect, there should also be a drain. Something has clogged a drain.

I don't know the specific layout of the Fit ductwork but I had this happen on an old RX-7. On older A/C systems, dust and mold will clog the drain. Since the car is relatively new, it is more likely a leaf has entered the air duct and clogged a drain where the duct curves into the passenger compartment.

It was a loose radiator cap. I lost a bunch of coolant, but not enough to overheat the engine, thank goodness. I topped off the coolant and the sloshing went away. The coolant level must've been at the same level as one of the hoses, because it certainly sounded like water flowing forward through a pipe when decelerating, then back the other way when accelerating.

I think youre hearing the fuel? since we sit on top of our fuel tank, I think if every1 would take some time to listen they would here it. Glad you checked everything tho, a loose radiator cap couldve been deadly to your car

It wasn't the fuel. I hear the fuel sloshing too, but this was different. No doubt about it.

nice, glad you found the problem!

Oh gosh! At least you fond it before any real damage could occur. Glad it's settled.