Water in rear of touring

[Be30]

CE60B88C-2BE2-4B0A-A608-30032A1186F2.jpeg

I spotted that the inside of my driver rear wheel well had water in it when I bought the car. I mopped it up and fixed the rust and filled it with stonechip.
After all the rain we’ve had recently I checked again to see it like this. Is there meant to be a drainage hole that was blocked which I’ve painted over?

[martauto]

CE60B88C-2BE2-4B0A-A608-30032A1186F2.jpeg

I spotted that the inside of my driver rear wheel well had water in it when I bought the car. I mopped it up and fixed the rust and filled it with stonechip.
After all the rain we’ve had recently I checked again to see it like this. Is there meant to be a drainage hole that was blocked which I’ve painted over?

One for you Brian

Mart.

[Cloggy Saint]

Could be a dodgy light seal, are they in good nick?

[Be30]

Could be a dodgy light seal, are they in good nick?

CFFC6673-9DBE-4FC4-BE3C-B902D310EF22.jpeg

Is this the rear light seal? The rubber trim all around the outside of the light?
If so then it may well be! It seems to have sunken too far in at the edge, if this would allow that amount of water in i dont know,,,,,, hope this makes sense!

[Cloggy Saint]

You'll need to take the light unit out to fully inspect the seal. What you can see is only a small part of it. They are a common cause of leaks.

[flybynite]

This is the rear light seal (arrowed) as Cloggy says you need to take out the light to see what state it is in.

41D2OT7zdAL.jpg

[paultv]

Dry it out, puff baby powder inside around the rear light housing and the side air flap then douse the outside of the car with water...you'll see the problem area easily.

The side flaps have crummy foam seals which rot easily and allow water ingress...

Is that the aerial drain tube connected to the side fresh air flap? check it also does not leak.

Paul

[Be30]

Thanks for all the replies!
I’ll get back tonight (hopefully in the light) and give it all a go.
Am I looking for cracks etc in the seal?
I’ll also try Paul’s baby powder trick, seems like a good shout in case it’s coming from anywhere else!
Cheers everyone

[BristolE30]

I had this problem for a while and found it was the rear light seal. Dry everything give it a hose down outside and you’ll quickly see the where it is coming from!

[Brianmoooore]

Dry it out, puff baby powder inside around the rear light housing and the side air flap then douse the outside of the car with water...you'll see the problem area easily.

The side flaps have crummy foam seals which rot easily and allow water ingress...

Is that the aerial drain tube connected to the side fresh air flap? check it also does not leak.

Paul

This is the way forward. Find out where it's getting in, not guess.
I've often read on here of faulty rear light seals, but I've never come across a single case of water in the rear of an E30 where this was the cause, other than one that had been smacked in the rear corner at some time, and the area in which the light sits hadn't been straightened properly.
A cause that I have come across though, on more than one occasion, is a loose fit of the 'shark fin' trims behind the rear side windows in their fixing grommets. These grommets are supposed to be replaced every time the trim is removed and replaced.
There is actually a drain hole in the bottom of each side pocket, formed by a pressing in one of the two pieces of metal at the bottom, where they are welded together, but this is supposed to be completely blocked by the factory applied sealant/underseal. I presume they are there to allow paint to drain out when the first primers were applied.

P.S., Paul, the aerial in a touring is a long way away from the air flaps in the rear! A very common problem on a saloon though, usually because the aerial has been replaced at some time, and no tube fitted at all.

[paultv]

Aah ok so is the tube in the photo from the rear window drain then?

Paul

[ocde30]

Not sure if the wells are different on a touring but just dug out these pictures of underneath my o/s well and there is clearly a drain hole in the pressing. At least that is always what I thought it was and have endeavoured to keep it clear.

Drain_hole_2.jpg

drain_hole_1.jpg

[Brianmoooore]

Not sure if the wells are different on a touring but just dug out these pictures of underneath my o/s well and there is clearly a drain hole in the pressing. At least that is always what I thought it was and have endeavoured to keep it clear.
Drain_hole_2.jpg
drain_hole_1.jpg

That's the drain, but it's normally buried in sealant. No difference in touring wells from any post facelift saloon, other than 325's ,with a rear mounted battery, have a hole in the bottom for the hydrogen vent tube.

[Brianmoooore]

Aah ok so is the tube in the photo from the rear window drain then?

Paul

Tube is the rear sunroof drain. Touring/M3 aerials are roof mounted, at the front, and don't have any kind of drain.

[Be30]

Update time!
Firstly i mopped up the water and then sprayed around the rear light area whilst sticking my head around to see if i could see any leaks. A tiny amount seeped through at the top corner but not too bad. I then sprayed over the top piece of trim mentioned by Brianmooooooore. A fair amount came down from here. I took the interior trim out and noticed that this must have been a leak for a while as you could see the colour difference of the path the water was following.
Luckily no rust.
Is it just the grommets that i would need to replace for the top “fin” above the rear window? I’m Glad I’ve managed to track down the leak, thanks everyone for their inputs!!