Water leaks!!

[geo1400]

Hi guys. I'm in the middle of fixing up my 318i for its MOT and i'm aware of really bad corrosion which is causing water to get in to the drivers and passengers footwells.

I know it is very common for water to get from the battery tray and behind the fuse box... but what is the solution to fix it!!

I've tried the fibregalss filler followed by sealants etc. but it lasts so long then water just gets in again!!.

Has anyone solved this prob on their own car?

If I have to weld, whats the easiest way to remove the fuse box?

Or should I give up and just focus my attention on trying to stop water getting in to the engine bay?

Any help appreciated cause the car's off the road so ideal time to do it.

Cheers, Geo1400

[kevin316i]

The water on the drivers side is probably caused by the scuttle drain pipe being blocked. You will see this on the engine bulkhead on the drivers side, it looks like an elephant trunk.

If you do proper surface prep on the rust hole around the fusebox trunk on the passenger side, fibreglass should work. Use fibreglass sheeting and work from inside the car. To seal around the trunk, use a flexible sealant like the one used for sealing around windscreens. Take out the glovebox to give you as much working space as possible.

I have repaired my own passenger side leak. Its not 100%, but I recon I just need to put on some more sealant as the water leak is virtually gone, just a tiny drop coming in. Carpert is staying dry, unlike when I bought the car

[geo1400]

The first time I tackled it I tried to get the fuse box out cause its under there that holes are. But I couldn't get it out so I went in from the glove box side with expanding foam!! This way I could see exactly where the holes are in the bulkhead. But I think the problem is the vent for the wiper motor, the water backed up over the years because of that blocked scuttle drain pipe and just rotted its way into the engine bay and footwell.

I'm gona try totally seal off the bonnet to stop water gettin in there and maybe try seal inside the vent again, or even block that off.

BMW make some of the best cars in the world but eh... there was a slight hic up with the design of this engine bay!!

Thanks for your response and hopefully someone else can shed some light on this, and moving to a better climate is NOT an option!!

[kevin316i]

If your'e looking to make under the bonnet as dry as possible, buy a new M3 type rubber bonnet seal, as it goes all the way down each side of the enginer bay along the wing.

I don't think expanded foam is waterproof as it is full of voids?