Water leak in trunk - Cars & Trucks

Hunting water leaks is a pain in the tailbone job to do. I'm assuming yours has the jack in the floor of the trunk, under the carpet.
The spare wheel well is the lowest point in the trunk so the water will collect there regardless of where the leak is. Start with the simplest tools, a flash light and the palm of your hand.
How much water is collecting and how fast does it fill up? Rain water coming up through the floor is unlikely unless the floor is damaged.
First take everything out of the trunk that wasn't in there when it came out of the factory. Take a really good look at the carpet and trunk side liners. Use the palm of your hand and feel the floor carpet for wetness. Your feeling to see if it is wet in a particular area. Using the flashlight look for darker patches as carpets often darken in color when wet. Move to the rear of the trunk and feel the liner on the back of the rear seats. Next run your hand over the side panels where the wheel arches are. This will give you clues as to where the leak is possibly coming from.
If the whole trunk carpet and liners are bone dry the leak is from under the car.
All the doors, the trunk lid and the sun roof are fitted with rubber seals to stop rain and road splashes getting inside the vehicle. Over time these perish and start to leak. Run your hand around the underside of the rubber seal the trunk lid sits on when closed. This is the most obvious place it will leak from. You can do this on each door as well because water can travel a large distance before it finds somewhere to create a puddle. A Sunroof can also leak but they tend to cause puddles in the foot well.
If you get a few dry days you can test for leaks with a hose pipe. Keep the trunk closed and make sure the inside of it is totally dry. Remove any spray nozzle from the hose so it flows at regular pressure. Carefully aim the water so it only flows over the trunk lid. Let it flow for a minute or two trying not to soak the doors at the same time. Turn off the water and leave the car alone for about 10 minutes. Wipe off any excess water on the trunk lid, open it and see if its now wet inside the trunk. Yes? the trunk seal is leaking. You can use this method for the doors and sun roof as well. Door and trunk seals are usually just a 'Push on/Pull off' fit so you can easily change them yourself.

Check the gasket where you put the gas in ..

These plugs are for draining water from the wheel well. There may be a leak behind the lights leave one of the plugs out for a day or too and see how it goes

its along way from the trunk to the back seat. check the back window,and the doors, get a water hose and have someone inside check it for a leak. Water in the trunk is usually caused by bad seals at the tail lights. But water in the trunk usually stays in the trunk and spare tire area. If the car has been wrecked, then who knows.

There is no drain plug. For the leaks be certain to investigate: sunroof drains, taillight seals, and the trunk seal. Many trunk seals actually channel water into the trunk. New designs are available on many GMs.

ls 400 - trunk leaks water. Fix -- Under the trunk seal at the bottom/rear you'll see that two pieces of metal come together. The adhesive / sealant that is used at the factory seems to leak with age. pull off the seal and use a good adhesive sealer to prevent water from leaking down between the two pieces of metal. Reinstall the trunk seal after it has dried and set properly.

When diagnosing a water leak, here's a handy tip. Check the accumulated water. If the water is dirty, look for leaks from the underside of the vehicle (floor, wheelwells, etc). If the accumulated water is clean, look for leaks from the topside of the vehicle (trunk seal, window seal, etc). To find where the water is coming from, shut yourself in the trunk with a flashlight and have an assistant run water over the trunk with a garden hose. You may have to remove some of the interior trunk trim to see exactly were the water is coming from, but chances are you'll find it. Also another common cause of water leaks are from impact damage, so check for collision damage repair. while your in there. -hope this helps.

same problem happened to my 2005 bonneville. inside the trunk and behind the carpet covering the wheel wells there are two water drain tubes. these tubes run down the inside of the "c" pillar and drain the water from the sunroof. they make a 90 degree bend at the bottom back of the wheel well(inside the trunk) and fit inside a round rubber tube/grommet at both of the rear wheel wells that lets the water drain outside.either the plastic 90 degree tube has come out of the rubber tube/grommet or the drain tube could be plugged up with debris. also make sure the two round rubber tube/grommets are installed correctly and seal the hole going through the trunk to the outside of each wheel well. this is of course only for those bonnevilles that have a factory sun/moon roof.

Mother nature is too slow in finding leaks. Have someone small get in the trunk with a flashligh and watch as you run a hose over everything. LET THE PERSON OUT!

How do you know the trunk seal is not leaking? Did you sit in the closed trunk while someone sprayed copious amounts of water over it? The other most common leak spot is from one of the tail lights. There is a goopy material that goes aroung the tail light that is supposed to seal it. You can usually pick this up at a auto supply store. It can also be coming from a body seam in the trunk. Check the lights and then check the body seams.