Water Leaking Inside the Car’s Passenger Side
Chris is Head of Content for FindTheBestCarPrice and is based out of Philadelphia, PA. As a seasoned automotive industry analyst and car enthusiast, he ensures the highest level of quality across all our content and curates our picks for the best deals each month.
Chris studied information systems and marketing at Drexel University and writes about a wide range of topics ranging from car buying tips to troubleshooting common mechanical issues.
When he’s not thinking about cars, he likes to stay in with his dog and make an “attempt” to finish a crossword puzzle (he’s not quite at the Saturday/Sunday level…yet). As a former cheesemonger, Chris still has a “sharp” passion for all things cheese, and his fridge is always loaded with it!
Finding water inside your car, especially on the passenger side, can be a frustrating and worrying experience. Water leaks can cause damage to your car's interior, including upholstery, electronics, and carpeting.
A water leak is a severe problem and should be fixed immediately. If ignored, leaks can lead to more severe issues, such as body rust, engine damage, or even a complete breakdown.
Let’s explore the common causes of water leaking inside a car on the passenger side, including problems with the sunroof, windshield, and door seals. Let’s also look at tips on how to diagnose the issue and what steps you can take to fix it.
Now, read on to learn more about how to deal with the issue of water leaking inside your car on the passenger side and how to prevent future leaks.
Table of Contents
Causes of Water Leaking Inside the Car Passenger's Side
If wet mats are regularly on the passenger side of your car, chances are there's a perfect explanation for that. The following are common causes of this phenomenon:
1. When You Have Leaking Windows
Rainwater can infiltrate a vehicle by permeating through weatherstripping on windows and windshields, which are the resilient rubber seals that encircle the glass surfaces of your vehicle.
As time passes, these rubber seals can deteriorate, becoming dry, brittle, and damaged, potentially leading to leaks.
When it rains, water can seep through compromised weatherstripping, finding its way into your car.
If you park your vehicle outdoors, ensuring its weatherstripping is optimal becomes even more crucial.
To prevent rainwater intrusion, you can have deteriorated seals replaced by a professional auto glass technician.
2. When You Have Leaking Doors
As per its intended design, water has the potential to infiltrate the interior of your car's doors, either from rainfall or from splashing caused by passing vehicles on wet roadways.
Ordinarily, any water entering the door should drain onto the road through designated drain holes.
However, these drain holes can become obstructed, forcing water into the vehicle's cabin.
Inspecting the undersides of your car's doors is advisable to ascertain if the drain holes have become blocked by debris.
3. When You Have a Leaking Heater Core
An unexplained puddle of liquid in your car's interior can be perplexing, but if it's not water, it's likely to be engine coolant.
Engine coolant is typically tinted in green, orange, or pink hues and emits a sweet aroma, often compared to maple syrup.
If you notice a puddle in your car's interior that cannot be attributed to rainwater, give it a whiff discreetly. If the odor is sweet and the liquid is brightly colored, it could indicate a potential leak in the car's heater core.
The heater core plays a crucial role in warming the air that enters the cabin when the heater is activated. It directs hot engine coolant through a system of fins, similar to a radiator, which spreads the coolant over a large surface area.
The blower fan forces air across the heater core, resulting in heated air discharged through the climate vents.
However, if the heater core becomes damaged or corrupted, it may develop leaks. Due to its location behind the dashboard, a leaking heater core can result in a puddle of coolant accumulating in the passenger's footwell.
Considering the importance of engine coolant in maintaining the safe operation of your vehicle, it is advisable to promptly seek the assistance of a reputable auto shop for inspection and potential repairs.
4. A Leaking Sunroof
If your vehicle has a sunroof, it's worth noting that the weatherstripping around the glass panel can also deteriorate over time.
The sunroof tray, which houses the sunroof and its mechanisms, is designed with drainage channels to divert water away.
If water seeps past the sunroof (or if it's left open during rain), it is meant to collect in the sunroof tray and drain out of the vehicle through special drains at the bottom.
However, if these drains become obstructed by debris, rainwater accumulating in the sunroof tray may back up and leak into the cabin.
Although the initial perception might suggest that the origin of water infiltration in your vehicle emanates from the sunroof or window, it is plausible that the water originates from internal sources within the vehicle.
Hence, it is imperative to meticulously examine all plausible points of water ingress, encompassing the sunroof and its intricate drainage system and other areas within the vehicle, to accurately pinpoint and rectify the root cause of the water leaks.
5. Blocked Air Conditioning Drain
If the heater core is not the culprit behind the water leak, another potential culprit could be the A/C evaporator.
Did you know that your vehicle's air conditioning system serves a dual purpose of delivering cool air through the vents and facilitating the expulsion of heat from the cabin?
As the A/C evaporator performs the task of extracting heat from your car, it also accumulates humidity.
Ordinarily, this condensation would drip onto the road as you drive, a common sight of liquid dripping from the undercarriage of a vehicle on a scorching day.
However, similar to the drain systems for the doors and sunroof, the A/C evaporator drain can also become obstructed. Water can amass behind the dashboard and seep into the front footwells when this occurs.
Fortunately, our proficient technicians can swiftly and effortlessly address this issue. In some cases, resolving the problem may entail elevating the vehicle, locating the A/C system drain, and clearing the obstruction using compressed air or other suitable tools.
How To Prevent Water Leaks
Here are three simple measures that can be undertaken by anyone to safeguard their vehicle against potential water leaks proactively:
1. Conduct Regular Inspections for Leaks
Regularly inspect your vehicle for any signs of leaks, particularly in the a/c system.
It is advisable to have your vehicle's a/c system serviced by a qualified mechanic at least every two years to allow for a thorough inspection of the evaporator for potential leaks.
2. Monitor the Sunroof Tray
Regularly check the sunroof tray for any indications of leaks. Additionally, ensure that the sunroof drains are free from obstructions to prevent water from accumulating and potentially leaking into the vehicle.
3. Address Cracks and Holes in Door and Window Seals
Inspect the door and window seals frequently for any cracks or holes that may allow water to seep into the vehicle.
Promptly repair any identified issues to maintain effective seals and prevent water ingress.
Proactively implementing these measures can significantly reduce the risk of water leaks compromising your vehicle's interior.
