[AntF]

Just noticed water in my boot for the first time - I often check having read these forums. Despite everything around the vents looking dry yesterday I took out the rear lights to get a better look and the seals were in pieces - RHS worse than the left with sections missing but both broken. My guess is the foam degrades over time and absorbs water making them expand and pop out of position. My seals were also very perished and easily broken. Surprisingly the seals are not available as a separate part, but even more surprising is the fact they are quite reasonably priced at around £10 each from Jaguar for the whole thing. At this price replacement is perhaps an easier fix than adding silicone and trying not to get it everywhere.

 

[AntF]

Hi, the foam seal I was referring to was the foam gasket around the plastic vents. On mine, the right hand one was in several pieces and the left was broken and appeared to be too long to fit in the groove of the vent - I assume a result of soaking up water as they have become perished. I have just put the new vents in this morning - less than £20 for a pair that includes the seals. When I first looked for a leak, this area appeared to be dry but after some rain I did spot some droplets of water getting through. They are really easy to replace and quite inexpensive so worth doing. The light clusters appear to not have a seal to the body, so water can get behind them, although the holes where they bolt through are sealed - I guess some of this water also runs over the vent seal and will eventually get in the car if the seal is damaged.
Pic is of the left vent - the right seal was in several pieces and some bits were missing.

 

[AntF]

There is a drain under the filler cap that can block - not sure if this water build up can get anywhere inside though, but a quick blast of air or a prod with a wire or similar will clear it out.

 

[AntF]

Have you taken them out completely or removed the light cluster to see how the seals are positioned? A pic earlier in this thread showed the seal sticking out of the top - I assume due to expansion. My old seals were saturated with water and could be squeezed out like a sponge - if yours are the same I would replace them as I would assume they shouldn't do this. I could see how they could seal for while and only start to leak when they become saturated and can't absorb any more water.
Have you tried getting into the boot with a torch whilst someone hoses down the area - sometimes the only way - or set up a camera recording in this area and see if you can spot any drops getting through from a hose.

 

[AntF]

Are the foam seals wet? My theory is they absorb water as they perish and eventually this reaches saturation point and water effectively passes through them. Mine could have water squeezed out and it hasn't rained for a few days. It's odd the talc isn't being washed away though. Have you cleaned out the filler neck drain too - not sure if this can cause any issues but it can't hurt to clear it out and check the pipe drains under the car. Hope you get it sorted - I know what it is like trying to track down a water leak - I had water getting into a Z4 that drove me crazy trying to track down the source.

 

[AntF]

Part number: C2D18113 £8.30 each plus VAT. This is the whole vent including the seal. They come with a nice VOLVO logo on them!

 

[AntF]

I think the fuel filler drain is to take any water away from that area as the filler cover it isn't sealed - it drains through a tube which (I assume) exits behind the bumper. Once cleaned you should see water coming out if you pour a bit in the top. Strimmer line is supposed to be a good thing to use for this.
Not sure of any other drain points - the bumper is open at the bottom and anything that runs down the rear window, boot lip and past the vents discussed, ends up down there. I looked for other points of entry and couldn't see anything obvious other than the rear window.
With the Z4 leak it was easier to find with less water sprayed onto the car - hosing it down seemed to do little but a spray similar to actual rain showed up the problem of a door card membrane leaking.

Everything I have read comes back to the vents - even if they are OK now and replacing doesn't fix the issue, you'll know they are good and it does seem that they regularly fail, so you are just changing them early.

I had put some kitchen towel under the vents in the boot having removed the seal after I spotted it was broken. With the vent in place but no seal the towel was quite wet with only light rain, so it clearly was getting through. My research suggest this could be more an issue when parked so maybe the angle you park at determines where and when the water enters the car. Just lucky my sub in the boot wasn't underwater and I caught it early. Also, I thought I had dried it out but there was a fair bit of water under the battery box that I could only get to by removing it, so the new ingress of water could actually be existing water, sloshing about when driving. Good luck.

 

[AntF]

There is a bung in the boot floor you could remove or make a hole in to keep any ingress to a minimum, but it isn't in the lowest point of the boot. I contemplated leaving out one of the battery box bolts to let it drain should this happen again.

 

[AntF]

You could use some draught excluder adhesive tape as a short term fix - it will be easier to remove than sticky silicone. But adding silicone may fix it and mean you don't need the vents. My local Jag dealer didn't hold these in stock so may be worth checking, if you are replacing them.

 

[AntF]

One more thing to check is the area around the fuel filler - this seems to be a flexible gaiter of some kind which could possibly allow water into the boot if it is split. Worth a close inspection with a torch to see, and if the drain hole is blocked it may make matters worse. My money is on the vents being the cause though.

 

[AntF]

Did you stop the water getting in?

 

[AntF]

Hi Bower, just wondered if you managed to sort where the leak was. After all the rain recently, I assume you have either a boot filled with water or you found the source of the leak.

 

[AntF]

Good to hear - hope the problem is fully sorted. I still keep checking for water on mine and so far all seems OK.

 

[AntF]

I also removed the light clusters when doing mine but it is possible to leave them in place and remove and insert the new vent through the boot. There is enough material on the vent to be able to pull them into place. Removing the lights allows you to clean out the crap that gets in there and is easy and quick to do though.
This seems to be relatively common as my son's Corsa had the same issue.