Water in rear footwells

[kartone]

Found the carpet & insulation soaking with water behind the driver & passenger seat after driving in the rain last week.
The floor drain plugs are all in place, I only left the sill plugs off to provide "ventilation"; front foot-wells perfectly dry; could not find any  water trails. Should I seal the floor drain plugs ?
 

[aggie57]

What do you mean by "sill plugs"?

[colcol]

You should pull the sill plugs out, i assume you mean the rubber plugs that are round 25-50 mm, they are most likely perished, and see if you can get some new ones from a rubber specialist, in Victoria, try The Purple Pig, Bill Thomson Auto Rubbers, Clark Rubber or Rare Spares, put the new ones in and seal them with a black bituman under body sealant, and open all the doors and windows and put a fan in your car to dry out all the water, before it starts to rust, Colin.

[kartone]

on the vertical part of he sill that faces the interior of the car there are 4 round holes approximately 25mm in diameter that allow access to inside the sill, mine are open to allow any moisture to vent to inside the car.
Started yesterday: removed seats & belts, folded away carpet & insulation and had hair-dryer going on low heat on-off for 8 hours with windows open.

[alfa duk]

 Does it have a sunroof?

[aggie57]

Certainly strange that both sides got that wet and I'd not have thought enough water would get through the sills to do that unless you drove through standing water.  Given you have the carpet out now perhaps you can get someone to spray a hose around that area and see if you can see the source?

[kartone]

No sunroof.
The strange thing is that only the rear passenger foot-wells had water, the front are pefectly dry.
Will try the hose test when it stops raining !

[Beatle]

Alfetta coupe?

Pull the door and rear side trims off and make sure the plastic sheeting is correctly installed to direct water down into the sills/bottom of the doors. 

Check water isn't coming in over the sill past the door rubbers

[Cool Jesus]

Kartone, Paul B seems to be on the money with your leak. Here's a couple of threads on the issue which both point towards the plastic moisture barrier on the door panels (although not 116 series). Don't forget there is also a moisture barrier below both rear passenger winding windows, which would be more pertinent to your issue.

http://www.ausalfa.com.au/viewtopic.php?f=4&t=5417&start=0

http://www.alfabb.com/bb/forums/gt-1965-1974/183081-advice-needed-window-winder-door-interior.html

[Beatle]

When you are disturbing/replacing the membranes, you need to take a real good look at how the factory installed them, and where the sealer/adhesive is routed. It's not simply a matter of applying a few dobs of glue and whacking on the plastic sheet.  The factory applied the sealer in a very methodical manner.   

Factory sealer is a bead of putty-like stuff with a string up the centre.  I've found something like windscreen mastic is a better substitute than silicone as it doesn't go off completely, and so can be re-used a few times without tearing the membrane, although it can be a bit messy.

Use thick clear/translucent sheeting when replacing the original membrane so you can see what's happening behind it.

You'll notice that the sealer is run in beads along the sheetmetal so that any water is directed to slots in the sheetmetal.  There should be no point where water can remain pooled against the plastic or sheetmetal. i.e. no complete 'U' shapes in the sealer without a drain at the bottom.  There are also beads of adhesive run above any holes in the membrane, like the window winder splines, door handles  etc.  Be aware that once you refit the trims, it can squish the sealer so it blocks drain holes so think about that when running your sealer.

If you just run tape around the edges of the new membrane, you will soon have water coming into the cabin area because the water will pool against the lower edges of the membrane and door frame.

Aftermarket speaker holes are almost always a place where water can come in.

Lastly, you need to imagine the membrane as a means of redirecting water to where it won't do any damage, rather than as a complete seal.  The insides of the doors will always get wet, so work with it, don't fight it.....

[alfa duk]

 Yep 100%, look at the seals and how water will run off the panels and you will soon see that water is supposed to run down the inside of the door and out the drains in the bottom of the doors/panels.

[Cool Jesus]

Here's an image of where the factory bead runs on the coupe doors. As Paul B said, its a non hardening product with string running thought the middle of it from the factory, so use an equivalent product when reinstalling.

[kartone]

Thanks for all the input CJ and PB. Will remove door & rear window inner panel next weekend to determine the status of the plastic lining.