2001 Ford Mustang, Water in Back Floorboard

(Birmingham, AL USA)

My 2001 Ford Mustang has water soaking the passenger side floorboard. Front passenger side a little moist, but really the rear is soaked. It has not rained since I got the auto (1 wk ago) so I know it's not leaking.



Steve Says,

Thanks for using my website! Most of the time when someone has a water leaking problem with their car it is because it is leaking into the front passenger side floorboard. Most of the time this is either because of a bad heater core or a plugged AC condenser drain.

You car problem is different because it is the back passenger footwell that is getting wet. The first thing you need to try to determine is what is leaking. It is most likely either just water leaking or coolant leaking. If you touch it and get it on your fingers coolant feels a little oily and smells kind of sweet (this is why animals like to drink it...then die because it poisons them). After you know what the substance is then you will know better what might be causing the leaking problem.

I know that some Ford Mustangs have had similar water leaks and the problem actually did originate from the front firewall. Something about how the floorboards are made channels the water to the back on some Mustangs.

So with all that being said I think the most likely cause of your problem is either a leaking heater core or an AC drain that is plugged. There are several ways to check which it might be. The first is to check your coolant level. If it is low that means that there is a leak somewhere. It could be leaking from your heater core (coolant runs through your heater core). If it's the heater core you will probably notice a good amount of water leaking into the cabin of your car. If this is the case then you need to replace the heater core. It is a big job so you might want to consider taking it to a repair shop.

If there is a small amount of water then you probably have a leaking AC condenser drain. This drain is supposed to drain all of the water off of the condenser as it collects. It clogs easily because it is a small tube that is prone to molding and growing algae because it is wet so much of the time. You can usually find it by crawling under your car (sometimes it's on the firewall) and looking for a clear plastic tube that is coming out of the floor or firewall. You can usually use a piece of wire ti stick up in it and unclog it.

I hope this helps with your water leaking problem. Let me know if you need more help by leaving a comment.