a leak
A water leak from the radiator in to the passenger compartment is usually a sign of a leak in the heater core. If the water is not from the radiator then there may be a leak in a window or door seal, or a hole in the undercarriage that is allowing water from the road to soak the carpet..
water in passenger floorboard, where is the hose that would cause this?
A leak some where in the system, such as a bad head gasket, a cracked head, a leak from the radiator, a leak from the water pump.
Its crying! Quick get some tissues! And Ice cream!
A leak.
If you can't locate a leak, inspect the EGR cooler.
The obvious answer would be that there would be a leak somewhere...
A large intake manifold leak. Check the boot at the throttle body.
No, it causes a massive coolantleak.
sand or some other type of abrasive mat in water supply,
Broken or split hose Radiator leak heater core leak