massive water leak - advice please.

[SS2115]

Is there any "favourite place' that the 850 leaks water to the drivers floor when the cars on a slope facing downhill?

We've had rain before and the Volvo's been bone dry.
However, for the last 4 days Sydney has had continual torrential rain that hasn't let up at all.
I got into the 850 this morning to move it and the drivers floor is ankle deep in water.

Its still raining so it was difficult to get out and down on hands and knees to look under the dash but there wasn't any signs of water around the windsceen and nothing dripping from under the dash.
All windows were up.
Headlining is dry (no sunroof anyway).
Vents all dry.
I lifted the bonnet and the drain vents around the fuse box in that well area are all clear and I couldn't see any pooled water. Down the gaps where the bonnet hinges are all looked clear.

Any advice?
Is this perhaps something common on these 850's with age or from new perhaps?

[humbertoflores63]

You need to clean up the drains at a few places:
1. The sunroof has 4 drains, two that face the front and 2 at the rear. The front one are easy to clean, open the sunroof and you will find the drains at the corners blow some air or make a funnel and run some water. The rear drains exit by the trunk next to rear wheel well. You need to unplug the drain tube and blow the air backwards towards the sunroof.

2. Where the wiper motor sits their is a large drain that gets plug with junk. It is next to the cabin filter, clean this!

3. The drain for the heater core can also get plug, look for how to replace a heater core and the back plastic hose is the drain.

[SS2115]

You need to clean up the drains at a few places:
1. The sunroof has 4 drains, two that face the front and 2 at the rear. The front one are easy to clean, open the sunroof and you will find the drains at the corners blow some air or make a funnel and run some water. The rear drains exit by the trunk next to rear wheel well. You need to unplug the drain tube and blow the air backwards towards the sunroof.

2. Where the wiper motor sits their is a large drain that gets plug with junk. It is next to the cabin filter, clean this!

3. The drain for the heater core can also get plug, look for how to replace a heater core and the back plastic hose is the drain.

Very much appreciate the fast reply.
1) there is no sunroof.
2) We are in RHD here - isn't the w/screen motor on the passenger side? Passenger floor is bone dry.
3) Isn't the heater core also on the passenger side?

Its only the drivers side filled with water. And because its on a slope, although ankle deep it luckily hasn't spilled to the back floor. So both back floors and the passenger side front floor are absolutely dry.
But I'm certainly going to check the drains you suggest under the bonnet for sure in case the area is filling up and overflowing to the drivers side floor.
Thanks.

[scot850]

Check the door bottom drains are clear. Over time they can get blocked and over-flow into the cabin. Also check the door seals are all fitting tight as again over time they can shrink and leave gaps. With the nose of the car pointed down hill, the water can run along the top of the door and they can leak near the door mirror area.

AS you have no sunroof, I am otherwise baffled. The seal around the cabin filter can allow water in if the drain in the area is blocked. Finally check the heater drain pipe in the middle of the car is clear.

Neil.

[SS2115]

Check the door bottom drains are clear. Over time they can get blocked and over-flow into the cabin. Also check the door seals are all fitting tight as again over time they can shrink and leave gaps. With the nose of the car pointed down hill, the water can run along the top of the door and they can leak near the door mirror area.

AS you have no sunroof, I am otherwise baffled. The seal around the cabin filter can allow water in if the drain in the area is blocked. Finally check the heater drain pipe in the middle of the car is clear.

Neil.

Thank you. Thats a great idea about the door filling up. I remember some of the BMWs were prone to this also on their back doors.
I'll check around the door seal as well.

Is the heater drain pipe inside the car or out of the firewall somewhere on the engine side?

[scot850]

It is in the middle of the car, on top of the center tunnel and to the right of the heater core. You may need to remove the inner kick panel at the front of the center console to see it. Having said that, it is as likely to flood both foot wells unless the car was leaning to one side. The heater drain runs out under the middle of the car just behind the transmission.

Neil.

[SS2115]

It is in the middle of the car, on top of the center tunnel and to the right of the heater core. You may need to remove the inner kick panel at the front of the center console to see it. Having said that, it is as likely to flood both foot wells unless the car was leaning to one side. The heater drain runs out under the middle of the car just behind the transmission.

Neil.

Okay - thanks.
The car was leaning towards the passenger side slightly with the road camber which means as you say the passenger floor should/would have gotten wet if this drain leaks to both sides.
But I'll be checking the drivers door for sloshing water and blocked drains for sure as this would be a prime suspect I would think.

[JimBee]

You have my sympathy! I went through this with my 93 850 following a hard rain when I first bought it in 2008. My left side footwell was flooded like you describe. I, too, was baffled. I thought of the sunroof and cleaned those drains. It happened again. Next, I cleaned the under-hood drain tubes by the firewall which I suspect was the cause.

But how did the water get inside? I theorized it leaked through the fuse box.

Still not sure but it has gone through many torrential rains since and has fortunately stayed dry inside. I do keep those firewall side drain tubes cleaned out.

Good luck solving it!

[cn90]

A source if windshield glass seal.
Sit in the car while it is raining and see if water seeps under the glass into the A pillar area.