Thanks for sharing. Does this leak reach both side compartments?

 

I have the same on the left side, where the amp is located. The sponge on the bottom is soaked.. no clue where it is coming from.

 

I had a leak on that side too, but not nearly as much. I found that it was probably coming from the rear sunroof drain entrance under the headliner as I mentioned in the original post.
I also found that a body seam was leaking on that side very close to the opening of that little carpeted flap (kinda below the tailight). I ended up siliconing the entrances to that seam also. I had to take the left side lining to get that those tho. Water was probably sneaking around the trunk seal. Might wanna check that.

 

Thanks for sharing this info. This is the first time I have read of a leak coming from this part. But, it does make sense. As the rubber and/or plastic age, they degrade and deform. Any sealing properties will fail and let water through. Good work!

 

Thanks!!
Yeah I was surprised when I noticed it too! Couldn't believe a leak could come from there and into the trunk.
Hope it helps some future users out.

 

Thanks to the OP for his fix, probably not the neatest but certainly effective:grin2:

Baas.J,
Have you tried the bootlid bumpstop on that side, had similar issues which took ages to find until I was looking for something else one day and stumbled across the leak.

 

How did you find out? And you just replaced it and it stopped the leaking?

 

I cannot remember what job I was doing but it involved removing the boot liner on that side, it had very recently been raining.
There was actually a drip of water on the bottom of it so I poured more water down the rear screen which then showed up by dripping through that bump stop.
I sealed my leak with silicon and it has been dry since.

 

I've got the same issue....water on both sides....i've even had a friend in boot, whilst I poured water all over....no visible signs of it getting in!
On top of that, it's screwed the control module etc, causing issues with the central display and the hand brake.

Did that happen to yours too? If so, how did you fix the issue with the control unit etc?

Thanks in advance
Ben

 

There are various causes for this - I'd think both sides would mean something other that the petrol filler surround. What model Ben?

 

Yeah, I suspect you're right smurkenstein.
It's a 2010 A5 coupe

 

Hey Ben- what did you discover? Which module was destroyed? How much was it to fix. Any help appreciated. Exact same issue!

 

Hi Guys,

This is my first post on here, so I apologize in advance for any screw ups. I usually just read these forums for help, and you guys have helped me a bunch already, so thanks everyone for all the help!!

So for the longest time, I've had a ton of water get into both of my trunk side compartments (where the fuses are mostly - passenger side - US car).
I've read almost every topic I could find, or at least tried to on this forum and didn't have any luck. I tried unclogging the sunroof drains, gas cap drain, water testing the little pressure vents in the trunk to no avail. Drove me nuts.

There was a small leak at the entrance of each rear sunroof drain where the drain tube meets the white connector (there's posts about this - decently common I've found). Peeled back the headliner enough for my to shove my finger in there and cover each with silicone. So far so good there.
However, that's not where most of the water was coming from!

Anyway long story short, I water tested every section of the car to isolate where the leak was coming from and I couldn't believe where I found it.
It was the GAS CAP AREA.
Not the drain, or the cap itself. It was the perimeter around where the cap meets the body of the car.
7 bucks later for a tube of black silicone and a bead around the fuel area and done. All sealed up!
Who would've thought?

Anyway, this was such a relief for me that I registered, made an account, and created this post in hopes that it helps others.

I've attached a picture of my "fix". Probably not the most ideal fix, but it was cheap and easy!
So if you've got water in your trunk area, maybe give this a look?

Thanks for your time!

Thanks Audisal v useful, and what was the best way to clear the water ?

 

Thanks Audisal v useful, and what was the best way to clear the water ?

 

Hey Ben did you remember to let yer mate out of the boot?????

 

I drive a 2011 S5 Cabriolet and it too had the dreaded water in the trunk compartments. I had no idea this was a thing until my rear view camera started acting up and after reading in the forum, I investigated. Low and behold, I found about four inches of water and my control module was submerged. Tried to dry it out but it only worked for about a day, then it completely died. Luckily, I found one on eBay; I was extra cautious to look for signs of rust or flood damage. There wasn’t any and it was a cinch to install DIY, with no coding required.
Now to find the leak entry point(s)! I have scoured all of the forums and YouTube and have been able to track down all likely culprits. Bottom line, no more water in the trunk area.
First, I cleaned and then applied AutoGlym to all the rubber seals. Next I cleaned all the drains. This I did with wire, trimmer line, compressed air, and lastly poured near boiling water into each drain to make sure they were actually draining. The five drains are located the right and left behind the soft top pillar and on the windshield. The last spot was in the filler cap area and this one was plugged the worst.
I can confidentially say one of these, or all of these were partially plugged causing the water egress but now my trunk Is bone dry. Lastly, I don’t see the water condensation on the inside windshield on a cold morning anymore. I will need to check the ac drains at the front of the car next.

 

Well done, good write up.

 

Hi Guys,

This is my first post on here, so I apologize in advance for any screw ups. I usually just read these forums for help, and you guys have helped me a bunch already, so thanks everyone for all the help!!

So for the longest time, I've had a ton of water get into both of my trunk side compartments (where the fuses are mostly - passenger side - US car).
I've read almost every topic I could find, or at least tried to on this forum and didn't have any luck. I tried unclogging the sunroof drains, gas cap drain, water testing the little pressure vents in the trunk to no avail. Drove me nuts.

There was a small leak at the entrance of each rear sunroof drain where the drain tube meets the white connector (there's posts about this - decently common I've found). Peeled back the headliner enough for my to shove my finger in there and cover each with silicone. So far so good there.
However, that's not where most of the water was coming from!

Anyway long story short, I water tested every section of the car to isolate where the leak was coming from and I couldn't believe where I found it.
It was the GAS CAP AREA.
Not the drain, or the cap itself. It was the perimeter around where the cap meets the body of the car.
7 bucks later for a tube of black silicone and a bead around the fuel area and done. All sealed up!
Who would've thought?

Anyway, this was such a relief for me that I registered, made an account, and created this post in hopes that it helps others.

I've attached a picture of my "fix". Probably not the most ideal fix, but it was cheap and easy!
So if you've got water in your trunk area, maybe give this a look?

Thanks for your time!

I have go to ask, why didn’t you clear the drain instead of covering it up?

 

Hi Guys,

This is my first post on here, so I apologize in advance for any screw ups. I usually just read these forums for help, and you guys have helped me a bunch already, so thanks everyone for all the help!!

So for the longest time, I've had a ton of water get into both of my trunk side compartments (where the fuses are mostly - passenger side - US car).
I've read almost every topic I could find, or at least tried to on this forum and didn't have any luck. I tried unclogging the sunroof drains, gas cap drain, water testing the little pressure vents in the trunk to no avail. Drove me nuts.

There was a small leak at the entrance of each rear sunroof drain where the drain tube meets the white connector (there's posts about this - decently common I've found). Peeled back the headliner enough for my to shove my finger in there and cover each with silicone. So far so good there.
However, that's not where most of the water was coming from!

Anyway long story short, I water tested every section of the car to isolate where the leak was coming from and I couldn't believe where I found it.
It was the GAS CAP AREA.
Not the drain, or the cap itself. It was the perimeter around where the cap meets the body of the car.
7 bucks later for a tube of black silicone and a bead around the fuel area and done. All sealed up!
Who would've thought?

Anyway, this was such a relief for me that I registered, made an account, and created this post in hopes that it helps others.

I've attached a picture of my "fix". Probably not the most ideal fix, but it was cheap and easy!
So if you've got water in your trunk area, maybe give this a look?

Thanks for your time!

God bless dude 🙏

 

I have the same problem on my 2011 A5 and just read your post. I'm on my way to the auto parts store. Thanks!