C5 x7 leak into boot

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Agour
(Donor 2026)
Posts: 141
Joined: 27 May 2018, 16:36
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C5 x7 leak into boot

Unread post by Agour »

The other week I noticed an inch of water around my spare wheel.

Water is running in from near the boot latch.

Looks like it's tracking along the insider lip of the boot, just behind the seal.

But... I can't figure out where it's coming in.

I found that a small amount could get into the boot lid, but I don't think that would then drain into the boot itself.

Any ideas? It seems to only be wet along the bottom edge of the boot, more so towards the left side.

Rear light seal seems fine.

I can't for the life of me figure it out...

The boot seal seems to be in good condition, so I don't think it's that
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owl
Posts: 88
Joined: 07 Oct 2025, 19:26
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Re: C5 x7 leak into boot

Unread post by owl »

Did you check bumper ventilation vents?
Agour
(Donor 2026)
Posts: 141
Joined: 27 May 2018, 16:36
x 8

Re: C5 x7 leak into boot

Unread post by Agour »

owl wrote: 09 Oct 2026, 19:08 Did you check bumper ventilation vents?
Do you mean the ones behind the side pockets?

There's a small amount of water behind the left one, but not enough that it would be running into the wheel well...

Unless there's more vents I'm missing?
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owl
Posts: 88
Joined: 07 Oct 2025, 19:26
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Re: C5 x7 leak into boot

Unread post by owl »

Agour wrote: 09 Oct 2026, 19:38
owl wrote: 09 Oct 2026, 19:08 Did you check bumper ventilation vents?
Do you mean the ones behind the side pockets?

There's a small amount of water behind the left one, but not enough that it would be running into the wheel well...

Unless there's more vents I'm missing?
Image
There are 2 air vents. 1 vent on the far left side (behind the rear wheel arch/quarter panel area). 1 vent on the far right side (behind the opposite rear wheel arch area). You need to remove rear bumper. When tracking down a water leak into the boot, it is highly recommended to check both sides, as the foam gaskets on both units tend to degrade at a similar rate over time.
Agour
(Donor 2026)
Posts: 141
Joined: 27 May 2018, 16:36
x 8

Re: C5 x7 leak into boot

Unread post by Agour »

owl wrote: 09 Oct 2026, 20:13
Agour wrote: 09 Oct 2026, 19:38
owl wrote: 09 Oct 2026, 19:08 Did you check bumper ventilation vents?
Do you mean the ones behind the side pockets?

There's a small amount of water behind the left one, but not enough that it would be running into the wheel well...

Unless there's more vents I'm missing?
Image
There are 2 air vents. 1 vent on the far left side (behind the rear wheel arch/quarter panel area). 1 vent on the far right side (behind the opposite rear wheel arch area). You need to remove rear bumper. When tracking down a water leak into the boot, it is highly recommended to check both sides, as the foam gaskets on both units tend to degrade at a similar rate over time.
ok got it, thank you. I;ll have a look :)
Agour
(Donor 2026)
Posts: 141
Joined: 27 May 2018, 16:36
x 8

Re: C5 x7 leak into boot

Unread post by Agour »

owl wrote: 09 Oct 2026, 19:08 Did you check bumper ventilation vents?
I found where the water is getting in!

On the sides of the boot are small overlaps in the bodywork, and it's getting in through those.. running along the bottom then into the wheel well.

Yellow arrow is where it comes through, and blue is the path it takes.

All the white lines were chalk to narrow it down.

I guess the vents are on the other side under the bumper?

I found a photo on this forum of a bumper off.. would you mind highlighting the vent location?
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owl
Posts: 88
Joined: 07 Oct 2025, 19:26
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Re: C5 x7 leak into boot

Unread post by owl »

Agour wrote: Yesterday, 23:56
owl wrote: 09 Oct 2026, 19:08 Did you check bumper ventilation vents?
I found where the water is getting in!

On the sides of the boot are small overlaps in the bodywork, and it's getting in through those.. running along the bottom then into the wheel well.

Yellow arrow is where it comes through, and blue is the path it takes.

All the white lines were chalk to narrow it down.

I guess the vents are on the other side under the bumper?

I found a photo on this forum of a bumper off.. would you mind highlighting the vent location?
Image
Image
It is located left and right ends. Do not buy new ones. I used a windshield silicone (black one). It must be dry at least 12 hours, more is super.
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owl
Posts: 88
Joined: 07 Oct 2025, 19:26
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Re: C5 x7 leak into boot

Unread post by owl »

Please check this video: minutes: 03:11