Many people complain that their car leaks and water comes inside during the rainy season, affecting interior components. It causes corrosion and mold growth in the interior cabin. In addition, water ingress also affects the electric wirings.
Why Does My Car Leak When It Rains? Your car can leak when it rains due to poorly sealed cracks and holes, broken weatherstripping, clogged door drains, incorrectly locked doors and windows, corroded or cracked undercarriage, damaged sunroof or clogged sunroof drains, cowling area, and rotted floorboard.
I was driving my car on the road during the rainy season and saw a water puddle under the dashboard. I checked the air conditioning and heating system, but their drains and vents were not clogged. I checked the cowled area and saw corrosion and a small hole, causing the problem.
I repaired the damaged cowl area with cowl vent repair patch panels. I installed it on the inner side of the dashboard, which is in the passenger area.
| Reasons | Solutions |
| Broken weatherstripping | Replace damaged weatherstripping |
| Poorly sealed cracks and holes | Seal the drilled holes |
| Clogged door drains | Unclog the door drain with metal wire |
| Incorrectly locked doors or windows | Ensure the locking of doors and windows before driving |
| Corroded or cracked undercarriage | Recoat the car’s undercarriage |
| Damaged sunroof and clogged drains | Properly close the sunroof |
| Cowling area | Patch the damaged cowl area |
| Rotted floorboard | Keep floor mats dry |
Broken weatherstripping
You can see water leaking in your car during the rainy season because of damaged seals of the door, windshield, doors, trunk, and hood area. These seals are the primary barrier against water ingress in the interior cabin.
These seals are made of rubber material, which can deteriorate with time, and provide an air and water-tight barrier to keep the passenger cabin dry.
The rubber material of the seals can dry and become brittle, which breaks easily. Broken rubber seals allow the rainwater to come inside.
The issue can also come from the warping of doors, hoods, trunks, and window seals. These can warp because of temperature changes and exposure to extremely high temperatures.
Moreover, UV exposure also causes drying and degradation of rubber material. Furthermore, accidental punctures and wear and tear of these rubber-based weatherstripping are also common.
Weatherstripping can also come off from its place because of the continuous usage of the specific component for longer. Frequent opening and closing of doors, windows, trunks, and hoods also increase the risk of their damage. You can also face the issue because of the loose rubber seals of these parts.
It is necessary to fix the broken seals of the windows and doors because it can also make the seats’ upholstery wet, and you cannot sit on them. My friend also experienced a broken window seal issue in his car, and he parked it outside during the rainy season.
The water wet the seat upholstery, and he had to remove it for cleaning. He cleaned the water puddle near the seating area and placed the dehumidifier and silica gel bags in the passenger cabin for water soaking.
He removed the damaged seals and installed the new ones there. He used high-quality adhesive to secure its connection on the sides of the window and create a water-tight seal.
Poorly sealed cracks and holes
Many people install aftermarket accessories in their cars to make them luxurious and upgrade their exterior look. Moreover, you can also add different aftermarket additions for driving ease.
Sometimes, you have to drill holes in the vehicle’s exterior body panel to install aftermarket accessories. You have to drill and seal the holes carefully so it does not cause water to get inside and wet the floor mats and seat upholstery.
The issue comes when you do not seal the drilled holes properly. Small holes near the drilled area cause the water to get inside when you drive or park your car outside during the rainy season.
Moreover, the issue also comes because of the failure of sealing material on the drilled hole surfaces. Sealants can come off from the applied surface because of temperature changes and exposure to adverse weather conditions.
It is necessary for you to properly seal the drilled surfaces to avoid water ingress in the passenger cabin. You should use a high-quality sealant that is resistant to moisture and changing temperatures.
Clogged door drains
Cars are equipped with drain pipes mounted inside the door panels. These drains allow water removal during car wash and rainy seasons.
Sometimes, door drains can get clogged and cause water to come into the passenger cabin. Because of the clogged drains, you can see water puddles under your vehicle seats.
Moreover, clogged drains also cause the water to collect near the door, leading to rusting. Clogging issues can come because of the contaminants, dust, and debris in water exiting through these drains.
Use the thin metal wire to unclog the drain holes of the doors. These are of small diameter and located at the bottom of the vehicle’s door. Clean the clogged drains carefully to reduce the risk of paint stripping.
Incorrectly locked doors or windows
Water enters your car during rainy weather because of partially opened doors, windows, hood, and trunk area. In addition, you can see water in the engine compartment when you move over the water puddles that are usually on the road during rainy weather.
It can affect the engine parts, and you can also have difficulty starting your vehicle because of misfiring and water in the combustion chamber.
You cannot close the doors properly because of the faulty locks or damaged latch mechanism. However, sometimes children cannot close the doors forcefully, which causes the leaking issue.
It is necessary for you to ensure that your car doors, windows, trunk lid, and hood are closed adequately before driving.
Corroded or cracked undercarriage
The undercarriage is the car’s lower chassis, made up of metal material. However, in some vehicles, it is coated with anti-rust sealants or paints to reduce corrosion risk.
The undercarriage is made of steel or aluminum, which can rust easily because of damaged paint and anti-rust sealant coatings. Corrosion eats the metal undercarriage, and you can see small holes there.
The undercarriage can corrode because of road salt exposure during winter, damaged protective coating, and scratched paint. People usually do not inspect the undercarriage regularly because you have to go under your car.
I prefer to coat the undercarriage of my vehicle yearly to prevent the rusting of aluminum material. Moreover, I pressure wash my car during the rainy and winter seasons to remove road salts and other elements that react with metal.
Damaged sunroof and clogged drains
Many luxurious cars have sunroofs for better airflow in the passenger cabin. You can see rubber seals near the sunroof for air and water-tight connections.
In addition, sunroofs also have drains that allow water removal during car washing and rain. Sometimes, these drains get blocked because of the debris and dust particles.
Clogged sunroof drains cause the water to leak inside the interior cabin. The most common symptoms of clogged sunroof drains are wet seat upholstery and high humidity.
You should close the sunroof completely to reduce the risk of water ingress. Moreover, clear the clogged sunroof drains for water removal.
Damaged cowling area
The cowl is the area in your car that covers the gap between the windshield and hood compartment. Its main function is to protect the area between the hood and windshield.
It keeps the unwanted elements away so it cannot affect the wiper and cabin filters. Clogging and rusting of the cowl area cause the water to leak under the dashboard.
You should use the vacuum cleaner to dry the passenger cabin before fixing the damaged cowl area because bacteria and molds can grow there. Use the cowl vent repair patch panels to fix the damaged area.
Rotted floorboard
Rotted floorboards cause the water to come inside during the rainy season. Floorboards can root because of the wet carpet and moisture exposure for extended periods.
Floor mats usually remain wet when you do not quickly soak up the liquid spillages. Accidental spillage of liquid drinks and outside temperature can make the floor mats in your cars wet.
Running the air conditioner and fan at high speed is better to reduce the overall moisture.
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