Door Membrane

bonbon

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Israel
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19L Auto
I have some leaking entering from behind the door cards. I've removed the cards and see that there are no membranes to prevent water ingress. :-?
Were there door membranes on 98 models?
Can I use a thick plastic bag sealed to door frame with a thin layer of mastik?
 

GazHyde

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My 99 model has a thin rubber foam type membrane on it. Not really sure what it actually is, as I've not seen a material like it before (I'm sure some one will tell me what its called)...

I can't see why some thick plastic cut to shape would be a bad idea other than if it creates condensation in the panels.
 

peteslag

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I found this how to on the web:

Cover all the gaps in the door metalwork with water proof duck tape. [if this sounds like a waste of tape, then you can fabricate a series of smaller 'inner membranes' using polythene - in the long run this is probably more time consuming however!] Take care to ensure that the tape is stuck down properly and that where the tape overlaps it is also stuck together properly.

Next, take a Polythene sheet bag (B&Q bags are ideal and free if you ask nicely) and cut it to the size of the door. This will form the new membrane. Stick this down very carefully with duck tape having made holes for the handle, mirror adjusters etc. Use the tape to prevent any splits spreading where you have cut the sheet.


Hope it helps ;)
 

bonbon

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I'm astill confused. The water is coming in from the centre of the sill- but if it was bia the window - how come the door card is not soaking. Perhaps it's creeping along from the door edges towards the lowest point?? ~x(
 

Warrior

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Rather than plastic why not try Tyvek, the stuff they use for damp prevention in building?
 

r37

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my 97 has a thick plastic sheet that sits directly behind the door card, it is cut out on the drivers side and i havnt noticed any leaking. If you do tape up all the holes just make sure to leave the drainage hole open in the bottom corner. If you go to a DIY store you can get pond liner by the yard and that should serve as a waterproof sheet.
 

Boysie

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Water proof duck tape and polythene/pond liner is a great idea
I would go for layers of duct tape, lapped
I have seen lots of cars that have had the membrane remove to fit door speakers
The owners dont realise it was put there for a reason
Fortunately days cars these days have speakers fitted from factory

Water finds it way to all sort of places
Horrid stuff if not found, costly repair :(
 

bonbon

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Re: Z3 leak via door sills

Caught it "wet handed".
Removed the cards - needles to say there were no membranes. The car originally had membranes as remnants of the black mastick which held them in place is still there.
Sprayed the window with a hose to simulate a downpour.
Well - as can be seen from the pic - water dripped both via and from behind the handle area to drip onto the lower rim behind the card. Which then entered the footwell by creeping over the sill. I will proceed to "manufacture" a membrane with thick plastic sheeting. I hope I am brave enough to test it before putting the card back in place.
I guess it gets worse with time as the rubber edging on the windows get older. Will also give them some gummiphledge.
 

Boysie

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Well done that man
Good picture
 

Snoops

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Well detected there.. be a satisfying job when you sort it
 

Boysie

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Snoops said:
Well detected there.. be a satisfying job when you sort it
Your smiley is sherlock
Different :)
 

Boysie

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its not a lemon entry
its water entry :D
 

JON

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while I am on about leaking hoods etc. , does anyone know where is the best place to buy a Crimson replacement hood , for the old 1998 Z3.....
 

GazHyde

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while I am on about leaking hoods etc. , does anyone know where is the best place to buy a Crimson replacement hood , for the old 1998 Z3.....
@badman gee had his hood replaced recently, along with some others.
 

spurs fan in a coupe

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As someone has already said, the Z3 came with a thin but strong foam type covering stuck on with a black substance similar to bitumen.

One with










One without

 

roadvoyager1

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The plastic liner is to keep water inside the body of the door as others have said, however, before you do your water leak test make sure that the holes in the bottom of the door are completely clear. These, as you may know, are the drains and can block with debris which can result in water being held in the door and later leaking out into the car. Unlikely to be a problem but very easy to check before you seal it all up.
 

vintage42

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Until 4/1998 the door liner was a plastic sheet that fitted either door — 51488397163. After that a molded rigid foam liner was used — 51488410037 left and 51488410038 right. The rigid foam liners are called "insulation", so sound deadening must have been their improvement. Both types of liners are adhered to the door by round 5/16” diameter butyl window sealing tape.

The door liners ensure that any water that enters the door by dropping down past the felt/rubber seal from the outside of the raised window, stays in the door. Water in the door goes out the door drains to the outside of the door sill and out of the car.

If the door liner was not there, water entering past the upper felt/rubber seal from the outside of the raised window, would drip and splash on the back of the door panel, run down the back of the panel and escape the interior of the door. The water would emerge from under the door panel, run down over the inner door sill, and into the footwell.

At the bottom and sides of the liner, the butyl tape is a critical seal that keeps water inside the door instead of coming out under the door panel.

The butyl tape is used at the top edge of the plastic liner to hang the floppy sheet in place while the sides and bottom are pressed into the rest of the tape. Since the rigid liner is self-supporting, the tape at the top was omitted.

Here's my plastic liner taped up for greasing the window sliders:



Note also that higher up inside the doors, the interior door handles have rigid foam covers stuck to the door with butyl tape, to keep water from getting on the door panel from the handles' holes in the metal. The slots are for the actuator rods to pass out of the covers.



A few days later...
I opened up my passenger door to lube its sliders. Its foam handle cover had fallen off like on the driver door. The adhesive looks like it came from a tube and was not applied in the right places. I will replace both covers using round butyl tape pressed firmly. I also ordered the newer rigid foam door liners to replace my flimsy plastic sheet liners.
 
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