Help!!! Water in trunk

[donky4444]

I know that the 2000+ models can have problems with water in the trunk. Has anybody found the cause of this? I drove my car from Kalamazoo to Grand Rapids in all that rain we had a about a week ago. I knew there had to be water in the trunk because I was getting condensation in the car. I fell and broke my leg the day that it rained the hardest so today was the first time I was able to look. Go figure, there was about 3 inches of water in the spare tire well. That was not fun to clean out with my leg in a cast but it had to be done. Now I need to check under the carpet in the backseat to see if there is water there. If anybody can tell me how to solve this problem it would help a lot. I'm not sure how much I can do with my leg but I need to get to it ASAP.

[myfirstbonnie]

Check the tail lights, reflector on the trunk, spoiler, and trunk seal. Easiest to climb in the trunk with a flashlight and close it and have someone spray the car with a water hose

[donky4444]

I think Darcy had it narrowed down to coming in from either a plugged sunroof drain or the rear shock towers. It only happens with hard rain and it never gets wet from washing the car.

[myfirstbonnie]

The sunroof usually leaks in on the carpet in the back seat. The trunk leaks will cause water to roll past the back seat into the carpet.

[Archon]

An addition to the list that myfirstbonnie gave, add the seal around the 3rd brake light. All those things were listed in a TSB regarding trunk leaks.

[skregal]

My trunk leak on my GXP was from the CHMSL or third brake light.

Here is a picture. You can see that someone in the factory didn't seat
it properly in the hole. The rubber seal was pinched and misaligned.


Mine didn't leak from washing either. I think driving it in rain pulled water
into the light from the wind flow over the deck wing.

Once I fixed that, no more water in the trunk.

[bonnevillain]

mine was just the seal

[naples1202]

Try and take out the carpet in the trunk and make sure if you have a sun roof that the hoses are not clogged and that the hoses are connected to flow out in the trunk. When I was rear-ended the dealer who fixed my car never reconnected my hose so that the water could flow out from my sunroof to the back.
Have any questions call me 863-521-2440
Garrett A> Lombardi

[2001SSEi]

I also recently started have water in my trunk, and found the sunroof drain hose on the left side of the trunk was disconnected. I am not sure how this happened, but I just reconnected it today and I will let you know if it stays dry after the next rain.

I hope this helps.

[GXP Venom]

Bolts that hold the GXP spoiler on have been an issue as well with some missing the seal washer.

[donky4444]

I pulled out all the trunk carpet the other day and it looks like it is coming from the top of the drivers side shock tower.

[willwren]

The only thing 'up there' is the trunk lid seal itself.

[bonnevillain]

could very well be the problem, that's what mine was. try the climing in the trunk and having someone spray it with a hose, it works great to pinpoint it

[blubyu]

I just fixed leak number 3 in my Bonneville (number 2 in the trunk). Leak number one was the right side shock tower. I sprayed undercoating around the spot it comes up through the wheel well. Leak number 2 in the trunk was a big one. I had about 2 inches of water in the spare tire well. Turns out it was coming from a seam on the drivers side. A piece of engineering brilliance (not) from GM. There's a hole in the trunk floor and side of car where the gas filler goes through. The entire area is covered with a metal cap and held in place with sealer. The seam was leaking. As you can see from the pics, on the wheel well side, there is zero sealer. There's a plastic access cap inside the wheel well. If you remove it, you can see the inside of the opening which is capped off inside the trunk. I put seam sealer all over the factory seam and cleaned all the gravel and mud from the wheel well side and sealed that also. You can see in the one pick along the base of the shock tower where the factory missed the seam entirely! I sealed that also, even though it didn't appear to be leaking. Looks like the union worker hit the end of the tube and just left it. Great quality control guys!

Here's a couple of the pics I took.
Pic 1 - pic of where factory missed a body seam entirely



Pic 2 - pic of where water was just flowing in from the factory seam holding cap in place



Pic 3 - View of cap from the wheel well side - no sealer from the factory at all

[ddalder]

I had noticed the water leak around one of the shock towers. The other location was one of the threaded studs that secure the black plastic trim in place across the outside of the car at the opening to the trunk. These studs are held in place by melting the plastic trim around them. One pulled out and when it did, the stud was loose in the hole. This allowed water to pass around it and into the trunk when it rained or otherwise got wet. This has been a problem in both my 2K+ Bonnevilles.

[CMNTMXR57]

Mine is from the sunroof. I tried to reseal it to no avail. I eventually fixed mine by drilling two small holes into the spare tire well at the lowest point and added a touch of paint to the hole edges with a q-tip.

No problems ever since. I figure if you can't beat it, let it do what it's gonna do, let it drain, and therefore no musty odors in the trunk, or risk of getting trunk items wet (which I've never had issue with).

[donky4444]

Mine is from the sunroof. I tried to reseal it to no avail. I eventually fixed mine by drilling two small holes into the spare tire well at the lowest point and added a touch of paint to the hole edges with a q-tip.

No problems ever since. I figure if you can't beat it, let it do what it's gonna do, let it drain, and therefore no musty odors in the trunk, or risk of getting trunk items wet (which I've never had issue with).

I did the same thing. I drilled two holes and sprayed them with etching primer and once that dried I put some paint around and on the edges of holes with a Q-tip.

I'm with you when it comes to letting it happen but let it drain as well.

[CMNTMXR57]

Great minds think alike.

[bonnevillain]

aren't there already holes there? they are just plugged with some rubber grommet things which i removed.

[ddalder]

I don't believe drainage holes are the answer. They may keep water from accumulating but doesn't prevent moisture presence in the passenger area or trunk (depending on where the leak originates). Obviously there must be a solution because not everyone's car has a leak. Long term there's just going to be more problems unless it's fixed correctly.

If the source is unknown I would try a leak detecting powder. If the source is known I'd obtain the right parts (as needed) and spend the time to tackle the problem.