Water In Trunk Of Car: 9 Common Root Causes & Their Fixes!

Water in trunk of car is more than just an annoyance; it may do serious harm.

In most cases, water will cause the floor pan and other metal parts to rust and will trigger the growth of mildew and mold on and under the carpet.

Short circuits and other damage brought on by water trunk in the electrical system are risky and challenging to diagnose and fix if they occur.

Repairing or diagnosing electrical problems can even rack up hefty bills.

Amazingly, this post unveils the most common water leaks’ roots and their fixes. Some can be DIY, while others involve an expert’s help.

Water In Trunk Of Car: What Are The Reasons?

Water in trunk of car

Water in trunk of the car can stem from these sources: door membrane, cabin filter, sunroof, door seal, air conditioning, windshield weather stripping, improperly installed lights, door weather stripping, and aftermarket accessories.

Door Membrane

A foam or plastic membrane is present behind the door panel to halt any water penetrating the door from entering inside.

It’s common to witness water leaks in car trunk when it rains. Water can go into the doors and drain through the holes in the bottom.

The liquid gets past the weather stripping on the door’s outer side drains through placed holes.

If there is a damaged membrane or clogged drain holes, water can seep into the door panel via them. While water collects in the footwell, examine the door’s bottom for dampness or discoloration.

Quickly dismantle the panel from the door and inspect the membrane for wear and tear.

Patch it with waterproof tape or alter it with a new plastic sheet if needed. Change your car’s weather stripping as well when it’s degraded.

Door Weather Stripping

It’s the thin strip of rubber lining outside or inside the car’s side windows. It keeps water out of your automatic window controls.

Water can sneak into the window if this part is not flush with the glass and then make its way through the door and into the car.

Check the weather stripping conditions and ensure it is flat against your windows. If it doesn’t work, that’s presumably causing your leak.


The most frequent source of automotive leaks is sunroofs. Water may flow through the sunroof and get inside the car once it is broken or not sealed tightly.

Examine the upholstery around your sunroof for signs of water stains and damage, and test your sunroof again to ensure it functions properly.

Door Seal

Set your eyes on the rubber seal lining the doors’ edge. Water will drip into the car via the door after the seal is torn or cracked, which is frequent in older second-hand vehicles.

Inspect the door seals to see whether the glue has failed or the rubber appears brittle or flimsy. Get a specialist to replace the seals, if any.

Windshield Weather Stripping

You can spot a weather seal on the front and back windows. Water can seep inside a vehicle whenever this rubber is poorly installed, old, or fragile. If needed, you must install a new windshield.

It can be the leak source on your dashboard or your trunk. It’s time to search for “the trunk leak repair near me” on Google.

Cabin Filter

In certain cars, the cabin filter is situated in the car compartment. It includes a cover and seals to keep water out of the cabin.

Leaks might develop via your car’s vent system if this seal degrades due to faulty installation or aging.

Air Conditioning

The car air conditioner‘s “drain tube” can be clogged for various reasons. This drain tube may send condensation away from the car’s interior.

Water may pool and deposit on the floor mat, trunk carpet, or behind the dashboard if it breaks.

If you’re having car issues, go for a drive without the AC and see whether the problem remains.

Should it persist and there are no other signs of leakage, it is probably the drain tube in the AC that triggers the problem.

Improperly Installed Lights

Following the taillights is an easy route for water to get into the trunk in most cars. Check the lights to see if there is a split in the plastic casing or it is not sealed properly.

Poor Aftermarket Accessories

A further big source of water leaks is shoddily installed aftermarket accessories.

Any roof-mounted accessory, such as a sunroof or rack system, can create a leak with improper installation.

Inspect the drains of the factory-installed sunroof. Sometimes, these tubes can get clogged.

Dangers Of Water In Your Trunk


Mold can grow thrivingly due to water in your trunk.

Since most trunks are lined with carpets, mold will dominate them in no time, notably in dark areas. At one point, large-scale black mold risks your health ungodly when you’re breathing them in.

The mold spores will become aggravated and enlarge as you put items in and take things from your trunk.

Black mold exposure over an extended period can result in major respiratory issues such as intensive coughing, eye irritation, sore throat, lethargy that never goes away, and recurring headaches.


Your car’s exterior is painted and prepared to withstand all types of weather. Still, there are times when rust will start to form due to salt, scratches in the coating, or other factors.

Your car’s interior can’t tolerate water. Suppose your trunk has spent too much time near moisture sources; it can eventually corrode inside.

If it’s located beneath the carpet, it retains much moisture for an extended period and grows severe corrosion.

Substantial rust damage in your car is expensive to repair. Since it mainly relies on the type, model, car year, and amount of rust involved, it is impossible to predict how much it would cost to fix.

It doesn’t break the bank with minor rust if you’re lucky. But while corrosion completely invades the trunk, you may have to spend a fortune on repairing it.

Foul Smell

The scent appearing after some time is one of the more undesirable outcomes of having water pouring into your car’s trunk.

This is particularly true when you reside in a tropical area since mildew will start to grow on the moist carpet. Scent can also permeate your vehicle’s cabin, which may be repulsive and dreadful.

One of the worst aspects of this stench is that it frequently persists.

Even after cleaning the carpet, stains may reemerge when moisture is exposed, especially on hot, muggy days. If you’re in the car for a while, that can get irritating.

Issues With Electrical Components

You might catch significant electrical issues based on the type of leak, its severity, and, specifically, which area of your trunk the water is running through.

If water gets into the speaker or the wiring for your taillights, it may lead to a short.

Other electrical parts, such as the battery in the trunk, are also included in certain vehicles.

Your car’s complete electrical system may go down if submerged in water. Sometimes, the electrical system may suddenly shut off while you’re driving.

The expense of changing your car’s battery is not too high, but the discomfort of your power system shorting out due to your wet trunk would be.

Not to mention the cost of hiring a tow truck to transport your vehicle to a mechanic for repairs.

Topics surrounding trunk issues do not stop here. You may encounter one more obstacle, like a trunk can’t close. Calm down and be wise in tackling such dilemmas.

Water Leaking Into Trunk: How To Diagnose & Fix It?

water leaks in car trunk when it rains

How To Diagnose

How to find water leak in car? Spotting the water pool is easy since it often ends up in the footwells. Even so, tracing its origins is notoriously tricky.

Water will collect at the lowest point. It also flows up wires and climbs cardboard and fabric surfaces.

You must locate the leak’s source. It may be the aftermath of a rainstorm or vehicle wash, parking the car on a slant, turning on the defroster or heater in winter, or from AC.

Knowing the time frame can help to determine the optimum fix.

When the leak persists without car cleaning or rain, the source is undoubtedly from the inside.

While the car is parked on an incline, you may get a broken weatherstripping seal, a clogged sunroof, or even an air conditioner drain.

How To Fix

Drying out the vehicle is only worthwhile if the leak roots are located. Nevertheless, once you do, make sure you dry out the interior completely to preclude mold’s rapid growth.

Mold might lurk in the carpet or behind the doors, making the whole car stink like a compost heap even though it appears clean at first glance.

It’s easy to get out the door panels, seats, carpets, and door panels and dry them in the sun. Use something absorbent, such as paper towels, to soak up the liquid.

After you’ve gotten everything as dry as possible, leave a plug-in dehumidifier or a plastic tub full of desiccant in the car overnight with the windows closed.

It takes some time for the whole space to dry up. Also, drive with the heating on and the windows open for ventilation.

How About Trunk Leak Repair Cost?

It’s up to you what parts fall victim to the water and need replacement.

Your usual repair bill will range from $75 to $180 for the tail light replacement. This is hugely affected by the brand, model, year of your vehicle, and typical prices your dealer charges.

It might take much work to calculate the expense of repairing a trunk’s weather stripping.

The costs will differ significantly from one model to another. This might fall anywhere between $100 and over $800.

The price to clear up the drainage area in a sunroof is about $125 to $200.

This relies on whether there is a simple obstruction in the tube itself or a worn-out or broken section of your line that needs changing.

Depending on where you reside and the car’s model and year, the cost of resealing your rear windscreen usually varies between $70 and $120.

In A Nutshell

How to find water leak in car

It can be hard to identify the source of water in trunk of car since it may be located somewhere other than where water is entering the vehicle.

To detect where the leak is coming from, it may be necessary to access the vehicle’s body by dismantling interior trim panels.

Share the post with others to help them better when facing such a condition.

Leave a Comment