Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.

Another trunk leak post...

Discuss problems you have had or are having with your Z4
Post Reply
csalexan
Newbie
Newbie
Posts: 5
Joined: Sun Feb 18, 2018 6:58 pm

Another trunk leak post...

Post by csalexan » Sun Feb 18, 2018 7:26 pm

Hi All,

I have a 2007 3.0si coupe and I noticed it smelled kind of bad when I got in it the last couple days so I started poking around seeing if I had somehow left a grocery bag in it or something and on a whim pulled the battery compartment tray off the floor and found about an inch of water in the compartment. I took the battery out and cleaned up all the water then started searching around for the leak.

What I found was that none of the carpet was wet from what I can tell, other than condensation on the under side of the battery compartment cover, and any carpet that directly touched that tray has also wicked water on the edges. But no dampness anywhere around the hatch or under the taillights as far as I could tell. So I started searching and it appears to be a common issue, I think I've read about 50 different threads on trunk leaks in the last 24 hours. I know at some point the best thing to do is probably start hosing it down and see if I can isolate it, but it's supposed to rain here for basically the next week straight and I wanted to get a head start on this.

So, a few questions after reading all the threads I could find:

1) As I said above, I see that the taillights are a very common leak point. I didn't find any water under or around them, but it had probably also been a couple days since it was in the rain. Is it possible for them to leak in somewhere under the carpet so it wouldn't be wet? Should I replace the seals just to be sure?

2) I've seen many references in other threads to air vents behind the bumper being a common leak point, however I've not been able to find any information on what anyone does to actually fix that, or even how to access them other than some mention of them being behind carpet somewhere. I've looked on RealOEM and can't seem to find the part either. Do those leak into the battery compartment?

3) It looks like the convertibles have a lot of problems with drains behind the soft top becoming clogged and backing up into the trunk. Since I have a coupe I can't have that issue, but are there other backed up drains that could be causing the problem? I saw a mention in a post about something around the fuel cap, but I don't see anything that looks promising on any of the parts diagrams. I also assume I would probably have wet carpet if that were the case. I just don't see how so much water got in without wetting the carpet anywhere that I can find.

4) When cleaning, I did notice some water sitting in the bottom of the big rubber grommet that the battery cables go in to head towards the front of the car. Now, it's totally possible the water already in the compartment just sloshed up in there when I was driving, or even that I splashed it up in there while cleaning, but I just don't know for sure. I found one post, that referenced another (unlinked) post, that said some people have driven through puddles and had water forced up into that channel and out the grommet into the battery compartment. It has been very wet here lately and, while I haven't driven through anything remotely dangerously high, I've certainly driven through a lot of puddles. Is this a thing that happens and is considered okay? Is there something I should be sealing to prevent it? In searching, I read horror stories of whole wiring harnesses becoming corroded from moisture and requiring thousands of dollars in repair, I certainly don't want that!

Anyway, sorry for the novel, I just wanted to provide as much information as I could. I appreciate any help you can offer.

Thanks,
Colin

User avatar
Dale_B
Member
Member
Posts: 733
Joined: Mon Sep 02, 2013 9:22 pm
Location: Northumberland

Another trunk leak post...

Post by Dale_B » Mon Feb 19, 2018 1:09 am

csalexan wrote: Sun Feb 18, 2018 7:26 pm
2) I've seen many references in other threads to air vents behind the bumper being a common leak point, however I've not been able to find any information on what anyone does to actually fix that, or even how to access them other than some mention of them being behind carpet somewhere. I've looked on RealOEM and can't seem to find the part either. Do those leak into the battery compartment?
Your problem will more than likely be this. I had the same symptoms you described.

The 2 vents will require replacing, they are cheap enough and relatively easy to replace.
Part number: 64226909340

After I changed these it fully cured the issue :thumbsup: I found removing the rear bumper (easy to do) was the best method to replace them.

User avatar
Dale_B
Member
Member
Posts: 733
Joined: Mon Sep 02, 2013 9:22 pm
Location: Northumberland

Another trunk leak post...

Post by Dale_B » Mon Feb 19, 2018 1:30 am

Found a picture which shows where they are situated....

Image

csalexan
Newbie
Newbie
Posts: 5
Joined: Sun Feb 18, 2018 6:58 pm

Another trunk leak post...

Post by csalexan » Mon Feb 19, 2018 2:54 am

Dale_B wrote: Mon Feb 19, 2018 1:09 amYour problem will more than likely be this. I had the same symptoms you described.

The 2 vents will require replacing, they are cheap enough and relatively easy to replace.
Part number: 64226909340

After I changed these it fully cured the issue I found removing the rear bumper (easy to do) was the best method to replace them.
Perfect, thanks so much for your help! I ordered the vents and went ahead and picked up two tail light gaskets while I was at it since they're relatively inexpensive also. Looks like it will be a few days until they ship, but I'll update the thread if it fixes the issue. Thanks again!

csalexan
Newbie
Newbie
Posts: 5
Joined: Sun Feb 18, 2018 6:58 pm

Another trunk leak post...

Post by csalexan » Mon Feb 26, 2018 1:59 am

Ok, I haven't received my new vents yet, but I took the bumper off this evening and I have a couple quick questions.

First, the center part of the bumper was a little tough to get loose from the clips. Once I got it free I discovered why: someone had put a significant amount of glue over three different areas at the top of the bumper. Is this normal? Should I be putting some kind of glue there when I reassemble it? I'll attach several pictures at the bottom of the post to show you what I mean.

Second, how do I actually get those vents out? They look like they are just pressed in place and held by friction, do I just pry them out? I didn't want to pry too hard until I received the new ones and could see how they are made, but they seemed pretty snug. Do I need to take up the carpet on the inside of the trunk as well, or can I do it all from the outside.

Once again, I appreciate the help.
Attachments
Z4_Bumper_05.jpg
Z4_Bumper_05.jpg (196.95 KiB) Viewed 627 times
Z4_Bumper_04.jpg
Z4_Bumper_04.jpg (188.79 KiB) Viewed 627 times
Z4_Bumper_03.jpg
Z4_Bumper_03.jpg (164.69 KiB) Viewed 627 times
Z4_Bumper_02.jpg
Z4_Bumper_02.jpg (190.65 KiB) Viewed 627 times
Z4_Bumper_01.jpg
Z4_Bumper_01.jpg (189.62 KiB) Viewed 627 times

User avatar
srhutch
Moderator
Moderator
Posts: 26959
Joined: Tue Jun 19, 2007 1:22 pm
Location: East Sussex, UK
Contact:

Another trunk leak post...

Post by srhutch » Mon Feb 26, 2018 7:57 am

There shouldn’t be any glue on that section. It’s quite a loose fit around there.
Image

csalexan
Newbie
Newbie
Posts: 5
Joined: Sun Feb 18, 2018 6:58 pm

Another trunk leak post...

Post by csalexan » Wed Feb 28, 2018 5:09 am

Alright, I got this done this evening with no issues, thanks again for the help everyone. For the sake of future generations, I'll give a little more information that I think might be useful. I'll attach two pictures to the post that will help show what I'm describing as well.

The vents are held in place by four clips total, two on each side, none on the top or bottom. From what I had read in other posts I was under the impression that I needed to pull the trunk carpet in addition to the bumper to access the clips for the vents. I understand why it seems that way, but after doing the first side I realized that it's not necessary. As long as you are replacing the vents and thus aren't worried about damaging the gasket on the old one, you can simply jam a plastic trim tool (or screwdriver if you wrap it in masking tape or are careful) into the gasket from the outside right where the clips are and you can pop them free easily. I've included a picture with arrows showing where to push. It really doesn't take much pressure to pop the clips free and once one side of the vent is loose, the other is even easier. It took me all of 10 seconds to remove my second vent with this method without having to pull the trunk carpet at all. Once you have the vents removed just clean the area where the gasket touches and press the new ones in until you hear the clips snap into place. That's all there is to it!

It's supposed to rain a bunch here tomorrow, so I guess I'll find out quickly if this was the source of my trunk leak!
Attachments
Z4_Trunk_Vent_02.jpg
Z4_Trunk_Vent_02.jpg (158.55 KiB) Viewed 603 times
Z4_Trunk_Vent_01.jpg
Z4_Trunk_Vent_01.jpg (112.72 KiB) Viewed 603 times

User avatar
1000rr
Senior Member
Senior Member
Posts: 1057
Joined: Thu Oct 13, 2016 10:53 pm

Another trunk leak post...

Post by 1000rr » Wed Feb 28, 2018 10:05 am

Do you need to remove the bumper?
Sterling 3.0, Bentley burgundy leather, Aeros..
Ducati Supersport S


Image

csalexan
Newbie
Newbie
Posts: 5
Joined: Sun Feb 18, 2018 6:58 pm

Another trunk leak post...

Post by csalexan » Wed Feb 28, 2018 2:47 pm

1000rr wrote: Wed Feb 28, 2018 10:05 am Do you need to remove the bumper?
Yes, although I've seen other people say they were able to do it from the inside without removing the bumper by popping the clips, pushing it out towards the bumper, then rotating it and sliding it back in through the hole, then reversing that sequence to pull the new one into place. So maybe a better answer is that you have to remove either the bumper or the carpet but not both.

User avatar
Dale_B
Member
Member
Posts: 733
Joined: Mon Sep 02, 2013 9:22 pm
Location: Northumberland

Another trunk leak post...

Post by Dale_B » Wed Feb 28, 2018 9:52 pm

Good to see you have managed to change them. Hopefully resolved your issue.

Post Reply