How to Dry Out a Car After Leaving the Sunroof Open | A Comprehensive Guide

You may be surprised to know that leaving the sunroof of your car open is way more common than you think. Returning to find a wet interior can be frustrating and concerning. Left unattended, it can cause untold damage that can be expensive to repair, so what should you do? 

If your sunroof has been left open, the most important thing to do is remove as much water as possible, using towels and a dehumidifier to dry the water absorbed into your car’s seats and floor. Once your car is dry, you need to have it checked for electrical damage and potential mould growth.

In this article, we will walk you through the steps to restore your car’s interior to a dry, clean, and safe condition. Read on for everything you need to know about drying out a car’s interior.

What Can Happen If I Leave the Sunroof of My Car Open While It’s Raining?

Leaving the sunroof of your car open while it’s raining can lead to a variety of potential issues and damage, such as: 

Corrosion of Internal Components

Rainwater can enter the vehicle through the open sunroof, potentially causing damage to the interior components. Seats, carpets, electronics, and other vulnerable areas may be exposed to water, leading to corrosion, staining, mould, and malfunctions. Restoring, repairing, or replacing corroded and water-damaged parts can be difficult or expensive. 

Damage to Internal Electronics

Almost all modern vehicles have electrical components located near the vicinity of the sunroof. This includes the car stereo, fuse box, speakers, and other electronics. Water that’s entered your car through the open sunroof can damage these sensitive electrical parts, leading to short circuits, malfunctioning electronics, fire hazards, and potentially expensive repairs.

Mould Growth

If rainwater enters the car through the open sunroof, it can soak into the upholstery and trim materials. This can result in water stains, discolouration, and potential damage to the fabric or leather surfaces. The warm, moist conditions of wet upholstery provide the ideal conditions for mould to grow. Mould causes bad odours and fabric deterioration which can pose health risks to those in the car. 

Mechanical Problems

Automated sunroofs have many components, such as motors, tracks, and seals. Continuous exposure to rainwater can cause these components to swell, corrode, or malfunction, which leads to issues with opening, closing, or sealing the sunroof properly.

Safety Hazard

Rainwater that enters the passenger cabin can impair visibility, fog up windows, and create slippery surfaces. All these pose safety risks for both the driver and passengers. Moisture on the controls or dashboard may also affect the driver’s ability to operate the vehicle safely.


Hydrolock, or hydraulic lock, happens when water enters the combustion chamber of an engine and prevents the piston from functioning properly. If water gets into the combustion chamber, it cannot be compressed like air, leading to a sudden stop of the piston’s movement. Remember that this rarely happens due to rain coming from an open sunroof. However, if it does, it can cause severe damage to internal engine components.

How to Dry Out Your Car After the Sunroof Has Been Left Open

If you accidentally left your sunroof open and rain gets in your car through the open sunroof, it’s important to take immediate action to dry it out and prevent potential damage. Here is what you should do if you’ve left the sunroof of your car open and the interior is wet:

1. Close the Sunroof

Start by immediately closing the sunroof to prevent more water from entering the vehicle. If the sunroof has a tilt function, ensure it’s fully closed. While it’s closed, check for any leaks around the sunroof. Tiny cracks and corroded rubber linings allow water to enter even when the sunroof is shut.

2. Avoid Starting the Car

It’s generally best to avoid starting the car until you have taken steps to dry it out and assess any potential damage. Starting the car without addressing potential water damage could lead to unpredictable issues, including faulty airbags, malfunctioning brake systems, or compromised vehicle stability. Also, attempting to start the vehicle with wet electrical components can lead to electrical malfunctions, short circuits, or fires.

3. Remove As Much Water as Possible

If there is standing water inside the car, use buckets, bowls or whatever you have to scoop out as much water as possible. Better yet, use a portable wet/dry vacuum cleaner; this can make the job so much easier if you happen to have access to one. Concentrate on low points where water tends to pool.

4. Use Towels to Remove Any Remaining Water

Pay attention to the floor mats, carpets, and seats, as these areas tend to absorb more water. Use towels, sponges, and paper towels to absorb the water. If the fabric of the seats is really wet, you may have to remove the covers to have them washed and dried off. Don’t leave them wet to prevent mould growth.

5. Check for Any Electrical Damage

There might be a chance that water has seeped into the fuse box, ECU, wires, and other electrical components. If water has reached any electrical components, it’s essential to have them inspected, assessed, and repaired by a professional. Water damage can cause electrical malfunctions, so it’s best to be on the safe side. 

6. Remove the Seats (if Possible)

If there’s an excessive amount of water that has gotten into the vehicle, you may have to remove the seats to access pooling water under them. Worse, the water may have seeped into the rails and components of your car seat adjustment mechanisms. Refer to your vehicle manual on how to remove your car seats. Once the seats are out, follow the previous steps to remove as much water as possible from these newly accessible areas. 

7. Open the Windows and Use a Dehumidifier

Open all the windows of your vehicle to allow the water to evaporate. If you have access to a fan or a dehumidifier, place it inside the vehicle to circulate air. This will help speed up the drying process. Position the fan in a way that maximises airflow throughout the interior.

8. Replace the Internal Air Filters

If your car has been exposed to water due to leaving the sunroof open, your vehicle’s internal air filters may be at risk. That’s because water entering the air filter can carry dirt, debris, and other contaminants. Even a little bit of water can be enough to promote mould growth in your air filters, which is one of the most dangerous places for mould to grow. Refer to your owner’s manual to check and potentially replace the internal air filters.

9. Use a Disinfectant to Prevent Mould Growth

After the car is dried out, it’s important to clean and sanitise the affected areas. Use upholstery cleaner or mild soap and water to clean the upholstery, carpets, and other surfaces. Use disinfectants and fresheners. This helps prevent the growth of mould and eliminate any lingering odours. If you’ve removed a lot of water, it may be worth having the car professionally cleaned and disinfected.

10. Allow Airflow to Dry the Car Naturally

Allowing natural airflow is an effective way to dry out your car after it has been exposed to water. Open the doors and windows to let the air in if the weather permits. If it’s sunny outside, park your car in direct sunlight. The heat from the sun can help evaporate moisture from surfaces and accelerate the drying process. 

Remember that drying your vehicle “naturally” should come after you actively remove the water (e.g. vacuuming the water out, wiping the dashboard dry, soaking up the water with a sponge, etc.)

Can You Use Heat to Dry Out a Car?

Using heat can be an effective method to aid in drying out a car that has been exposed to water. There are a few different ways of using heat to dry out your car, such as: 

Natural Heat

Park your car in direct sunlight to take advantage of the sun’s natural heat from the sun, which evaporates moisture from wet surfaces. Be aware that this can potentially damage certain materials or components inside the car if it’s left in the sun for too long, so keep an eye on the temperature and your car’s interior. 

Interior Heating 

Turn the heater to its highest temperature setting and run the fan high. This circulates warm air throughout the interior, aiding in the drying process. Open the windows to allow moisture to escape.

Portable Heaters 

Portable heaters can be used to introduce warm air into the car. Place the heater in a safe and stable position, making sure it is not in direct contact with any surfaces that could be damaged by heat. Point the heater towards the wet areas, and adjust the temperature and fan speed accordingly. Monitor the drying progress closely; avoid leaving the heater unattended.

Avoid excessive heat that could potentially damage or warp interior components, electronics, or materials. Use mild or moderate heat levels to prevent any warping, weathering or damage caused by direct heat exposure.

How Long Does it Take For a Wet Car to Dry?

Generally, it takes at least 24 to 48 hours for the car to dry thoroughly. However, this can vary depending on many factors. These include the severity of water exposure, amount of ventilation and airflow, weather conditions, and the methods you employed to dry your car.

Related Questions

Can You Air Dry a Car by Driving It?

Yes, you can dry a car by driving with the windows down, although it isn’t the most efficient or effective method for drying out the interior. Driving will allow the moving air to dry some surfaces, although it may not reach all areas of the interior that require drying.

Why Is There Water in My Passenger Footwell After Rain?

There are a few reasons why water accumulates on your passenger footwell, including leaks from the sunroof or window seal, a clogged drainage channel, a damaged or cracked door seal, or a faulty windshield seal. 

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