Massive water leak but can’t find it. Help

[S80D5rs]

Hello everyone.
Newbie here 👋🏻.

So I have an 2008 S80 D5. I have a few small issues but first a rather large wet issue.

I’ve notice over time a sloshing noise when cornering then it would disappear. Down here in Cornwall we’ve have ridiculous amounts of rain recently and the sloshing is back with more water in the car than our reservoirs, the rear N/S footwell is well like a well and literally within days of wet vacing.

Further investigation revealed that under the rear seats was soaking and the only the rear N/S footwell.

The sloshing sounds like it’s from the B-pilar and sill, not the front that seems to be the common problem.
Front areas are bone dry and the boot is bone dry just under the rear seats and n/s rear footwell.

I do have a sunroof but front drains are clear can’t see the rear drains but the runners on the sunroof are dry even in wet weather.

Can anyone help

[Olaf Els]

A liberal coating of talcum powder is a good way to observe where the water might be coming in.

I'd remove as much of the trim around the offending area as possible, including the rear seats if there's water under there. Then dry everything off, first with a towel and then with a hair dryer. Once it's absolutely bone dry, coat all the bare metal and fixed insulation with shaking of talc. Any water coming in subsequently will leave a track in the talc. It's then a matter of working out exactly how it's getting there.

[SnineT]

Sounds like you may need to remove the arch liner and see what's going on behind there as it might be getting in through the front of the cill.

And are you sure it's in the frame and not the doors?

[Lancee]

Is the water inside the door ? Check the drain holes in the bottom of the door ?

[rcpilot]

you might be suffering from the dreaded volvo plague and that is a leaking windscreen, this is a common problem with the P3 shape. this is a good method to see if it is leaking, use some shaving foam spread it down the "A" pillars outside and along the roof joint, then from the inside gently blow compressed, air around the edge of the windscreen if it is leaking you will see bubbles coming through the foam, check this out watch from start to finish you will be surprised at where the bubbles come out,it can be repaired diy or if you can afford it a new windscreen

[Tatsfield]

Professionals may be able to remove the screen, clean the mating faces and reseal it. Trying to insert sealant into the gap is not usually successful. If you really want to try, don't use silicon. it won't work. Windscreen sealant is the only option. Volvo used to do the job FOC but have withdrawn their support . Even when they did the job they would not pay for a new screen if the old one was damaged in removal. Best to speak to a Volvo dealer and see if they can offer you any sort of deal on what is a very well known fault.

[rcpilot]

If it is the windscreen joint then volvo will not look at it for free, the only fix, if you do not try to reseal it your self, is to get the windscreen replaced autoglass will give a lifetime guarantee but it wi cost you £850

[SnineT]

I guess he must've sorted it by now, shame no update though.