Water leak
Moderator: martauto
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Dwood
- E30 Zone Newbie
- Posts: 6
- Joined: Sat Apr 20, 2019 9:43 pm
It rained heavily the other day an my central locking went mad I've found that the fuse on the relay has gone and needs resoldering on but when I've taken it out there is small amounts off water in the box I can get my hand down to the bottom of the cavity and there's no puddle so not a bad leak and the carpets and all the well is dry but there's obviously a leak does anyone have any ideas where it comming in from? There is like a long pipe or something going from the upper wing to the bottom that I can move around pretty lose is that some ki d of drainage pipe?. The car has been all welded and the bottom of the pillar to the scuttle has been de rustified could there be something there that's not been re fitted properly? Cheers
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ah
- E30 Zone Addict
- Posts: 2518
- Joined: Mon Mar 10, 2008 11:00 pm
- Location: surrey
First things first what E30 are we talking about,Touring,Cab,2 door,4 door,what year ect
Born on the 23 April 1990 320i Alpinweiss ll kabriolett! (SOLD BUT NOT FORGOTTEN !)
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Brianmoooore
- E30 Zone Team Member
- Posts: 49359
- Joined: Mon Jan 10, 2005 11:00 pm
There's almost certainly no leak, just inadequate drainage. Contrary to what most assume, the cavities, such as the sills and inside the doors of cars, are not supposed to keep water out, just ensure it doesn't get into the cabin.
This also applies to the sunroof. The seal is just to prevent wind noise, and is not intended to keep water completely out.
Water that gets past the sunroof seal is collected in an internal gutter system, and then has a choice of four pipes to go down, depending on what angle the car is at. The two rear pipes deposit the water behind the sides of the rear bumper, but the front pipes run down inside the A pillars, and discharge into the sills, where there should be three drain holes each side for the water to pass through and drop onto the ground.
It sounds like your drain holes are blocked (often by overenthusiastic application of underseal) and water has built up in the sill to a sufficient depth to flood the locking ECU. This often results in the ECU powering all the lock motors continuously, burning out all the motors in the locked position, so, if you can still get into the car, you have at least been partly lucky.
Dry the locking ECU out, and resolder the link, but DO NOT use any extra solder. The existing stuff is a special solder with a very low melting point, and adding ordinary solder risks burning out the wiring looms (and possibly the car) under certain fault conditions.
There's no guarantee that the ECU has survived, so at least make sure a window is open when you refit and test it, in case it decides to lock you out.
This also applies to the sunroof. The seal is just to prevent wind noise, and is not intended to keep water completely out.
Water that gets past the sunroof seal is collected in an internal gutter system, and then has a choice of four pipes to go down, depending on what angle the car is at. The two rear pipes deposit the water behind the sides of the rear bumper, but the front pipes run down inside the A pillars, and discharge into the sills, where there should be three drain holes each side for the water to pass through and drop onto the ground.
It sounds like your drain holes are blocked (often by overenthusiastic application of underseal) and water has built up in the sill to a sufficient depth to flood the locking ECU. This often results in the ECU powering all the lock motors continuously, burning out all the motors in the locked position, so, if you can still get into the car, you have at least been partly lucky.
Dry the locking ECU out, and resolder the link, but DO NOT use any extra solder. The existing stuff is a special solder with a very low melting point, and adding ordinary solder risks burning out the wiring looms (and possibly the car) under certain fault conditions.
There's no guarantee that the ECU has survived, so at least make sure a window is open when you refit and test it, in case it decides to lock you out.
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Dwood
- E30 Zone Newbie
- Posts: 6
- Joined: Sat Apr 20, 2019 9:43 pm
The car is a 2 door if that helps?..
Oh right I never knew that I was thinink something along those lines Tbh the car is fine generally I've been to work and back in it a few times it seems fine but it did splutter a couple of times but wasn't sure if that was related. Yes the car has been re undersealed so that could be correct I have no puddles in the car though, all carpets dry just a small amount on the relay box for the central locking as if it was dripping onto it.
Where about am I look g exactly for these drainage holes and am I right in there's one under the wiper arms?
Oh right I never knew that I was thinink something along those lines Tbh the car is fine generally I've been to work and back in it a few times it seems fine but it did splutter a couple of times but wasn't sure if that was related. Yes the car has been re undersealed so that could be correct I have no puddles in the car though, all carpets dry just a small amount on the relay box for the central locking as if it was dripping onto it.
Where about am I look g exactly for these drainage holes and am I right in there's one under the wiper arms?
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Brianmoooore
- E30 Zone Team Member
- Posts: 49359
- Joined: Mon Jan 10, 2005 11:00 pm
On the outside of the car, there is a vertical strip, about 20mm deep, that runs the full length of the bottom of the sills. If you look under the car, you will see the drains, formed on the reverse side of this vertical strip. There are three each side, one at the front, one at the rear, and one just forward of the middle.
The drains near the wipers are for the scuttle box, which water gets into through the two grills in front of the wiper arms. There's a triangular drain at each end of the scuttle box, which leads into the area above the wheel arch liners under the front wings. These rarely give problems.
There's also another drain from the scuttle box in the engine compartment, near the back of the cylinder head, to the right of centre, commonly known as the elephant's trunk. This can block, and when it does, water can flow down through the heater casing, and into the passenger compartment.
There isn't likely to be water dripping on the top of the locking ECU, unless the sunroof drain has come adrift or is rusted at the tray, and if there was, it shouldn't cause any harm, since the ECU case is waterproof from above, when mounted on its bracket.
The drains near the wipers are for the scuttle box, which water gets into through the two grills in front of the wiper arms. There's a triangular drain at each end of the scuttle box, which leads into the area above the wheel arch liners under the front wings. These rarely give problems.
There's also another drain from the scuttle box in the engine compartment, near the back of the cylinder head, to the right of centre, commonly known as the elephant's trunk. This can block, and when it does, water can flow down through the heater casing, and into the passenger compartment.
There isn't likely to be water dripping on the top of the locking ECU, unless the sunroof drain has come adrift or is rusted at the tray, and if there was, it shouldn't cause any harm, since the ECU case is waterproof from above, when mounted on its bracket.
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Dwood
- E30 Zone Newbie
- Posts: 6
- Joined: Sat Apr 20, 2019 9:43 pm
I have just tested it water flows out through the front drainer in the cill drivers side. The elephant trunk was pretty blocked and pretty brittle now as I broke trying to get it off does anyone have a part number for them please?..,
But Ive had my had down where the central locking relay goes an I can feel very small amounts still there after testing. There is like a long black pipe conduate thing running down from the top by the wind to me it just feel like a pipe with nothing in it so is that a drainage pipe or something?
But Ive had my had down where the central locking relay goes an I can feel very small amounts still there after testing. There is like a long black pipe conduate thing running down from the top by the wind to me it just feel like a pipe with nothing in it so is that a drainage pipe or something?
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Brianmoooore
- E30 Zone Team Member
- Posts: 49359
- Joined: Mon Jan 10, 2005 11:00 pm
Pipe running down into the sill is the front right drain from the sun roof. Park the car so that it is facing downhill and leaning to the right, open the sunroof, and pour some water into the gutter around the aperture. The water should all appear out of the pipe in the sill.
Elephant's trunk is 51 73 1 911 369
Elephant's trunk is 51 73 1 911 369