C5 X7 Water under rear carpet

[Ceenine]

Upon doing some trailer wiring I needed to lift the rear carpet. To my disappointment (understatement) I found both undersides of the rear carpet, being absorbed high density foam were soaking in water. I say water because it didn't look discoloured enough to be coolant. I don't recall having to top up the coolant either which seems to rule it out. The car is kept undercover at all times which should rule out rain. It doesn'tof course rule out water coming though the firewall. However, going by the difficulty I had finding a gap in the firewall, including rubber grommets I can't believe water has got through there.

If I had left a window open during heavy rain, I suspect that water would pool on the top rather than seep around the edges and find a wayunderneath the carpet. I suggest it is well nigh impossible for water to seep through the carpet.

Any inspiration?

PS We haven't had any heavy falls of rain here in 12 months, only 730mm (28") of fairly light falls.

[myglaren]

Screenwash or coolant should give themselves away by the smell. Coolant feels sticky too.

[Ceenine]

Not coolant, pure Tasmanian water I p

[Gibbo2286]

This can be caused by blocked back door drains or if the plastic lining behind the door cards has been ripped or omitted by some previous work. It's usually just rainwater.

[GiveMeABreak]

1) Check underneath each door - there are holes for water to drain out that become blocked
2) The scuttle drains where the wipers are can become blocked.

The following items are for water evacuation:
(12) is cowl water evacuation tube
(14) is the water draining gutter

But first of all, check the holes under the front wheel arches - here's a video from a previous post on this - but you'll have to watch it in YouTube as the owner has prevented embedded playing of it.

[Ceenine]

Marc, I can find one only drain tube passing down to the opening behind the mudguard lining on the right hand side. This opening picks up drainage also from apertures where the windscreen wipers sit. Do you agree in relation to the sole tube?

I can no longer purchase documentation on Service Citroen. Most frustrating and a marketing negative by PSA.

[Xantippa]

I had rear door water holes blocked with stickers. They were installed at the factory. There was several liters of water in both doors.

[GiveMeABreak]

Marc, I can find one only drain tube passing down to the opening behind the mudguard lining on the right hand side. This opening picks up drainage also from apertures where the windscreen wipers sit. Do you agree in relation to the sole tube?

I can no longer purchase documentation on Service Citroen. Most frustrating and a marketing negative by PSA.

That's correct, just one - but I would focus on the rear doors first as if it was the front scuttle drain blocked, then I would first expect water into the front cabin floor well and you'd notice that way before it went to the rear. I put the diagram up for the front and the video as these will in all likelihood become blocked at some point.

Water gets in via the window rubber at the base of the windows and through the window channels - not just via the rain, but more importantly with pressure washing, - which many forget about and these can be your worst enemy. Water is forced into the seals and into the window channels and can over time fill up the door cavities. This leads invariably to the window regulator wire rusting and then 'pop' all of a sudden when you come to use it!

So do check the bottom holes in the door - there may be something internal blocking them from the inside, like some sludge or algae build up. Once the water gets to a certain level, it will leak out of the door card, onto the footwell area and under the carpet where you won't notice it until you're swimming