Water leak from under dash

Post Tue Jan 20, 2015 10:05 am

Hi, after having a quick search I couldn't find the answer so I thought I'd ask for some advice. I've got a water leak from under the drivers side footwell/dash which I can't find. I've dried the car out and have no carpets in at the moment (rally car) if I pour some water onto the windscreen and it drains into the hole behind the wing (under screen in o/s corner) I get a trickle of water that flows in to the footwell. I Do have a roll cage that goes through to the strut tops but I've re sealed that as thought this could be the problem. I've taken the wing off to try to rectify the issue but I can't see where it's coming from. I've also re sealed around the battery. It's only a minor leak but as I'm contemplating turning the car into a useable daily drive it needs to be sorted out. Any ideas guys? Thanks in advance for any replies!

Post Tue Jan 20, 2015 10:09 am

Examine the RH stud that the glove box hinge fixes to. Does it show signs of rust where it's welded to the bulkhead?

Post Tue Jan 20, 2015 10:15 am

I'll have a look. It does seem to be coming from above where the bonnet pull would be ( mine doesn't have one) on the right hand side (o/s) of the car in the corner. The car doesn't look like it needs welding. All painted white too making it easier to see. Will do some investigating! Cheers

Post Tue Jan 20, 2015 10:48 am

kipsy wrote:I've got a water leak from under the drivers side footwell/dash which I can't find.
(under screen in o/s corner)

Brianmoooore wrote:Examine the RH stud that the glove box hinge fixes to. Does it show signs of rust where it's welded to the bulkhead?

Glove box is on the passenger side.

Ben

Post Tue Jan 20, 2015 10:51 am

kipsy wrote:I'll have a look. It does seem to be coming from above where the bonnet pull would be ( mine doesn't have one) on the right hand side (o/s) of the car in the corner.

This is confusing. The bonnet pull is on the passenger side (n/s). Left hand side on a RHD car.

Ben

Post Tue Jan 20, 2015 10:53 am

Have you looked behind the battery and the sound deadening?

Look up as far as poss under the dash too...

Post Tue Jan 20, 2015 3:44 pm

My car doesn't have a bonnet pull sorry. Thought it was on drivers side. It also
Has no interior. It seems to come from up under the front wheel arch battery tray area. Runs down into the throttle pedal area. I've sealed up the battery tray. The water seems to enter the car when I pour an amount in through the drain under the windscreen that goes into/by the wing?

Post Tue Jan 20, 2015 4:48 pm

Dry it out then sprinkle talcum porwder over the area. Then pour water into the vent.

The trails in the talc should lead to the leak.

Ben

Post Tue Jan 20, 2015 5:26 pm

You can normally see a trail coming from up under the dash in the corner. I can see where the trail comes from approx but can't seem to stop it. I'll have another look when I got 5 mins.

Post Tue Jan 20, 2015 8:40 pm

Have you removed the drivers side wiper and the plastic vent?

Water can collect in the corner on the left.

Also if you have a sunroof there is a elephant trunk style drain is it blocked?

Post Tue Jan 20, 2015 10:04 pm

There is no sunroof cheers. I removed the vent and there is no blockage. If I pour water into the vent the hole it drains into is how it seems to be getting into the interior. Can't see how to stop it?

Post Tue Jan 20, 2015 11:39 pm

Elephant trunk is there, sunroof or no sunroof. It drains the centre section of the scuttle box, and is nothing to do with sunroof drains.
Any water that gets into the scuttle box should exit by the 'elephant's trunk', or one of the triangular holes at each end, into the area behind the wheel arch liners.
If it's leaking into the cabin, it's either via a hole, which should be easy enough to find and deal with, either by direct observation or by the talcum powder method, or (the reason for my glovebox stud comment) the sealant at the bottom of the scuttle box has failed.
The bulkhead in an E30 is double skinned, with the two skins separating at the top to form the bottom of the box. If the sealant fails, water gets between the two skins, and rusts the bulkhead from the inside out, with the glovebox mounting stud usually being a casualty.

Post Wed Jan 21, 2015 9:14 am

Is there any know way of re sealing it if the water has got/gone between the inner and outer skin? Thanks for reply

Post Wed Jan 21, 2015 12:28 pm

One thing to note, I seem to have a soft patch on each side that leads to the wheel arch, I have highlighted this here:

Now my scuttle box is fine as this seems to be a single skin piece that leads from the cabin to the top of the inner wheel arch.

Might be worth a prod as mine looks ok but feels "soft"