Rear footwell leak

[Marko320]

Hi all. Sought advice from you guys in the past, thanks. Would now appreciate advice on fixing a leak in o/s rear footwell on my 1988 320 cab. Car is off road until March and while taking out front pax seat I lifted rear carpet and saw bottom foam part of carpet was drenched, top of carpet is dry. The leak appears to be coming from an area that looks like it has a large plug, it was covered by some kind of sealing cover and when I pressed down on it, I could see the water being squeezed out. I have chipped away this cover to reveal mastic which I assume seals said large plug and I am assuming this has perished and needs replacing. Car hasn't been on road since October and I can only remember driving on Mway in torrential rain once for about an hour the month before. No leaks in roof. I haven't looked underneath properly yet due to my mobility, a small garage and the cold!

My question is, can you tell from photos if plug is just worn out, or does it look like a dodgy repair and is it something that could be far worse like rusty floor? Rest of floors all look ok but notice a small bit of what looks like surface rust leading from back area.

Apologies for going on so long!

[Brianmoooore]

The round plug you have found is a very common place for water to leak into E30s. Unfortunately, it's not the only place that the water may be getting in.
The plate is held in place by three tabs around the edge of the disc, that fit through three corresponding slots around the hole in the floor, the disc is then rotated to lock it into place, and sealed with seam sealer. Rust usually attacks one of the tabs, the disc is then unsupported around two thirds of its circumference, the sealant cracks, and water finds its way in.
If the disc is loose then at a minimum it needs to be removed, the old sealant removed from the area, and then refitted with fresh seam sealer. If a tab has rusted off, then new ones are available from BMW. If the rust has spread to the floor pan, then my usual solution is just to weld a plate over the area.

[Marko320]

Thanks Brianmoooore, methinks this will keep me busy!

Marko320

[gingerrusta]

Where else could this come from if this area is ok ? I have the same problem

[Brianmoooore]

If the ONLY place that is getting wet is this area, then it's very likely the plate is the problem, but there are many other places that water can leak into an E30, and some of it find its way to the rear floor area.

[gingerrusta]

What about in the horseshoe department ? I've noticed water sitting on the drivers side of the car where the roof hinges fold down to when the roof is down .

[BenHar]

What about in the horseshoe department ? I've noticed water sitting on the drivers side of the car where the roof hinges fold down to when the roof is down .

Don't think the OP was about a cabriolet.

But this is the answer to your question:

http://www.e30zone.net/modules.php?name ... drain+hood

Ben

[e30topless]

What about in the horseshoe department ? I've noticed water sitting on the drivers side of the car where the roof hinges fold down to when the roof is down .

Don't think the OP was about a cabriolet.

But this is the answer to your question:

http://www.e30zone.net/modules.php?name ... drain+hood

Ben

the op's is a cab and yes that should fix it !

[BenHar]

the op's is a cab and yes that should fix it !

Oops, I should have read it properly.

The way to tell if it is coming from the roof well is to lift the rear seat squab. Water from the roof well pools under the seat before getting to the foot well.

Ben

[gingerrusta]

What about in the horseshoe department ? I've noticed water sitting on the drivers side of the car where the roof hinges fold down to when the roof is down .

Don't think the OP was about a cabriolet.

But this is the answer to your question:

http://www.e30zone.net/modules.php?name ... drain+hood

Ben

the op's is a cab and yes that should fix it !

Checked these and they aren't blocked but still got wet rear carpet both sides

[Brianmoooore]

Wet anywhere else?

[gingerrusta]

No I checked the front carpets and they are dry. Just the rears .....a˜ž

[Brianmoooore]

If the ONLY place that is getting wet is this area, then it's very likely the plate is the problem.

[BenHar]

The way to tell if it is coming from the roof well is to lift the rear seat squab. Water from the roof well pools under the seat before getting to the foot well.

Ben

[gingerrusta]

Does it make a difference that the car has not been on the road for a while ? As these plates would leak with water coming from underneath the car ?

[Brianmoooore]

Makes a considerable difference! Is this a cab. or saloon?

[gingerrusta]

Cabriolet

[gingerrusta]

Roof doesn't leak ...

[BenHar]

Is there any water under the rear seat squab?

Ben

[gingerrusta]

You mean if I pull up the rear seat bench part ?

[BenHar]

You mean if I pull up the rear seat bench part ?

That is exactly what I mean. I'm not sure what else the words I wrote could have meant?

Ben

[gingerrusta]

That is dry under that .

[gingerrusta]

Is there any water under the rear seat squab?

Ben

Sorry ben just wondered what a squab was .

[BenHar]

Is there any water under the rear seat squab?

Ben

Sorry ben just wondered what a squab was .

No problem.

If it is dry under the seat base then it is not the horse shoe drains.

Ben

[gingerrusta]

So if it's wet just on the rear carpets behind the seats both sides where else could it come from ?
Door rubbers
Window rubbers

[Brianmoooore]

Are the plastic films over the doors, behind the door cards, intact?

[e30topless]

Don't think the OP was about a cabriolet.

But this is the answer to your question:

http://www.e30zone.net/modules.php?name ... drain+hood

Ben

the op's is a cab and yes that should fix it !

Checked these and they aren't blocked but still got wet rear carpet both sides

How did you check them ?

[gingerrusta]

the op's is a cab and yes that should fix it !

Checked these and they aren't blocked but still got wet rear carpet both sides

How did you check them ?

Yes check both and are not blocked .

[gingerrusta]

Are the plastic films over the doors, behind the door cards, intact?

I don't know on the plastic film . If they weren't there how would water get to where it is without leaving a mark on the back of the door card ? Wouldn't the door card swell ?

[Brianmoooore]

The outer window seals are not supposed to be completely waterproof, and a certain amount of water will find its way inside the door frame when it rains. Depending on whether the car is parked on a slope or not, if the film is missing or damaged, this water can run out from behind the card at the bottom and into the cabin.

[gingerrusta]

Thanks Brian moooore I will check this out. If the outer window gaskets on the rear windows aren't the best would water get into the rear here ? I would assume the water would drain out somewhere ?