Water Leaking Into Car Floorboard – Wetting Carpet
DennisB WiseAutoTools.com © Summary: Water on the floor of a car is normally from one of three sources. With a little common sense and knowledge of what the possible causes are, just about anyone can determine what the problem is. Depending on what the problem is and what the source is for the unwanted water the repair might be done by a do it yourselfer. Some repairs are NOT a DIY project. First thing is to identify the problem and go from there. Read on for repair tips on how to keep your feet dry as they should be.
Outside water entering the passenger compartment – Rain water is the first common cause of water on the floor, soaking into and wetting the carpet of a car or truck. Common sense tells us that if the water on the floor and only appears when it rains or we drive through a car wash, it’s an outside water intrusion problem. Also if it’s clear water and NOT green or some other color that is usually used for antifreeze, you’ve eliminated the possibility of the heater core leaking. More on that in a minute. Leaks can come from worn seals or doors that are simply “out of adjustment”. Leaky windshield seals are harder to pinpoint because of the dash obstructing the view along with the trim panels possibly hiding where the leak may be. Convertible tops are notorious for having water leaks. Even brand new convertible cars are likely to have small leaks that nothing can be done about. Sometimes drains for a Sun roof can be clogged, causing the water to back up into the passenger compartment. Seals around doors and windows can sometimes have tears or be worn to a point that the water can enter.
One sign that water could leak in from rain is excessive wind noise when driving at highway speeds. If replacing a seal does not fix a water leak there could be a more complex problem causing the issue. The adjustment of the doors or seals may be required by a specialist. Names for these professionals may vary depending upon the area of the world or country you are in. In the Tampa Bay Florida area, these guys are called “water doctors”. Don’t underestimate how hard the job can be. As an automotive technician, I’ve spent hours before trying to repair a window seal leak. At the end of the day I had tried everything I could think of to no avail. I normally didn’t spend that much time on a problem like this, but it was a slow day. After giving it my best shot, I accepted defeat. Carmax had to call the water doctor!
Inside water leaks are typically caused by a leaky heater core or an A/C water leak. The heater core will obviously leak coolant (antifreeze) providing you have the correct mix of antifreeze in your radiator. Checking the water that’s soaked into the carpet is the first step in checking the type of leak that has occurred. Take a small cloth or paper towel and extract some moisture from the carpet. If using a white towel or cloth, the color should be easier to determine. You could always wring the towel and squeeze the water into a cup for examining. If the water is clear, it’s likely that the water leak in your car is from the air conditioning drain water. It’s normal for water to drain off the A/C evaporator coils/fins, but it is obviously not OK for it to drain into the passenger compartment. Usually this is caused by a clogged evaporator drain. Every evaporator case (or air distribution box) has a drain for this water. If leaves or other debris accumulate in the case the drain can become plugged. See the following article on Car AC Water Leaks for info on how to take care of these types of AC water leaks. If there’s coolant instead of clear water then the heater core is likely the culprit. See the following repair article on Car Heater Blows Cold Air for more on that topic.
Question – My 2004 Camry LE is leaking lots of clear water into back passenger side floor after using air conditioner. Have tried to find the AC drain tube but there is only a hole with no tube coming out of it. I’m thinking it could be pushed in. Can I access this from front passenger side floor? How difficult is it to remove carpet and do I have to remove glove box or part of dash? Thanks RoseAnn.
Answer – RoseAnn, sounds like evaporator water, since it’s clear and only happens when running the AC, is leaking inside and running underneath the carpet. There are sometimes channels underneath the carpet in the floorboard that allows this to happen when there’s a leak. I’ve seen water go all the way to the back, passenger foot area before without soaking the carpet too badly elsewhere. Most cars either have a plastic tube sticking through the firewall or a rubber tube (or both). This should be seen from the outside with the hood up on most cars. To “fix it” or more accurately clear the drain, I’d try using a coat hanger or compressed air in the actual drain tube to free the blockage. In some cases you may be able to remove the blower motor in order to access and clean the case out. Leaves seem to accumulate there on a lot of cars. If you cannot clean it out that way, the glove box area will need to be disassembled, the refrigerant recovered and the evap case (usually just the part behind the glovebox on Toyotas) removed for thorough cleaning. The small case can be split (taken apart) for cleaning. It is comprised of two halves. The carpet would only have to come out if it had been totally saturated and the problem has been occurring for awhile and if there’s a problem with mildew as a result. To remove the carpet, first all the seats and console would need to come out. The padding underneath the carpet, called jute, is usually replaced rather than cleaned. The carpet itself can be cleaned and allowed to completely dry before reinstalling. Of course you want to check for leaks and verify the repair before installing the carpet back into the car. Good Luck.