Why Is There Water Where My Spare Tire Is? – Reasons and Solutions!

Water, where the spare tire is, is quite common and unusual because you might wonder how it got there in the first place. The tailgate was closed, so how can you have several inches of water there?

This article covers the water there, how to remove it and what to do to apply a permanent fix.

Why Is There Water in the Spare Tire Compartment?

Both leading causes found water in the tire well and have the same thing in common: it doesn’t happen overnight; we are talking over a month or so. Few people check the pressure on the spare tire and only go in the boot if you have a puncture and need to fit the spare, so water in the trunk can go unnoticed for many months. If it fills quickly, you need to apply a permanent fix quickly.

Leaking rubber seals

Usually the seal, which acts as a weather strip that goes around the trunk, will have a join; over time, the rubber dries and shrinks. The gap between this join becomes slightly more significant and you no longer have a water-tight fit. The water runs to the hole, seeps in, and fills the tire compartment behind the carpet. The other issue with the rubber seal is it can get damaged and crack with age, so it is no longer watertight.

If the tailgate is damaged or not lined onto its hinges correctly, you might see a gap where water will also get in on rainy days. There is nowhere for the water to go other than gather at the lowest point in the car, the spare tire well.

Another seal that has been known to cause a problem on certain cars is the tail lights. Replacing the light unit after changing a bulb it sometimes doesn’t get a good seal, allowing water to pass through and get to the bottom of the tire well again.


An excess build-up of condensation in the car, you’ve most probably seen on the inside of the windshield. This also happens on the inner rear window and drips into the tire well. Condensation builds happen because there is probably a leaking door seal or gap in the boot lid. The cold area outside at night gets into the car, and you get the condensation build-up on the windows.

Rear windshield washer

The rear windshield washer has pipework that runs to the tailgate from the engine bay. Any leaks from broken pipes, or cracked housings means the water drips down into spare tire well. Usually this is pretty obvious, as the spray on the windshield won’t be very powerful when operating the washers.

How to Get Water Out of the Spare Tire Well

Removing the water from the spare tire well as soon as possible is very important. Not only are there electronics in the trunk, some even have fuse boxes, and if they get wet, it can cause short circuits. There is also a hazard to your health which is explained more below.

Remove the drain plug

Almost all cars have a removable plug in the floor of the tire well. However, you cannot get it back in after. It has to be pushed out with a hammer and chisel to allow all the water to drain. You can cover the hole with good tape or find a rubber bung to fit. Protecting the hole to stop rodents from nesting in from the trunk is wise. Covering the hole also aids with the reduction of road noise inside the cabin.

Dry with towels

If you are experiencing a small amount of dampness, try to keep this as dry as possible. Remove the spare wheel, dry it off and dry the boot well with an old towel or paper towel. Before you put everything back, make sure it’s dry. You may need to do this every couple of weeks over rainy seasons, but you probably won’t ever need to do anything during the summer. So, it is entirely possible to keep drying the spare tire and the tire well regularly and live with the problem.

Use a wet vac

A wet vac or water extractor will help to suck some of the water away. You may even need one to extract the floors and trunk liner moisture. Towels can soak up any remaining water. The whole trunk must be completely dry to prevent further issues from appearing, allowing the trunk to air out on a lovely sunny day.

why is there water where my spare tire is

How to Fix Water in the Spare Tire Well

Replacing the seal is very simple; the boot seal peels off, and the new one pushes on the metal lip around the trunk. Some cars have the seal glued into place. The problem is diagnosing the seal that is causing the problem.

To diagnose the faulty seal, check for any water staining on around the seal, including any metal work. You may need to remove the carpet in the trunk to see where the water is coming in. From there; you can trace it back to identify the offending seal. You may even spot a big chunk of the seal missing without much effort; in that case, a replacement will help, if not solve the issue.

Signs of a Bigger Problem

The main problem with having a damp car interior is mold. Some indications are that mold is starting to appear even if you removed the water from the spare tire well weeks ago. The surrounding carpets will remain damp until dried.

First a damp smell

Look out for a damp, musty smell when entering the car or opening the trunk. A damp smell signifies the carpets are still wet or at least humid, which is a good place for mold to grow. Mold requires cold muggy conditions to appear in the car.

Mold appearing

Mold is harmful to you and your passengers; it can cause you to feel quite unwell. The problem with mold is once it starts to appear, it spreads like wildfire and will very quickly consume the whole of a car’s interior before you know it.

You should check the underside of the trunk carpet as that is the first place for it to appear when there has been water in the spare tire well.

Depending on how bad it is, you may need to remove the carpet and trunk liner and use chemicals to kill the mold spores. Most automotive detailers will have encountered cars with bad mold problems andhave experienced removing mold from car interiors. So, it is worth considering paying someone to do this for you. If you do not remove the mold, it will come back quickly.


Removing water from the spare tire’s location should be done as soon as you notice the problem. 90% of cars have a removeable drain plug in the trunk to get rid of the water, but you probably won’t get it back afterward. It can be difficult to remove if mold starts to set into the fabric trunk liner. You may need a detailer to clean the car and destroy the mold.

My name is Tom although my friends call me Tommy. Messing around with cars and bikes has always been a hobby of mine even from a young age. So I made it my day job 17 years ago. I am a fully qualified mechanic as you would expect. I've worked in all different areas of the motor trade, valeting, panel beating, engine repairs, I'm sure you get the idea. I enjoy sharing my wealth of knowledge and experience with others, which is the reason I spend a lot of time here writing for this website.

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