Interior water leak ...

[RoddyC4S]

Hi all.

I'm getting water leaking into my C4S. It's a coupe non sunroof model.

It's pooling up inside at the rear of the passenger side inner sill where it meets the rear wheel tub. I've removed the rear side trim and the water pool can be seen when looking in from the rear speaker aperture and the front seat belt anchor point.
I'm can't see any water tracks from the side window so I'm sure it's not that.
Drips of water are also coming in from the rear window at the bottom passenger corner, I have all that trim removed and the drip comes in from the inner structure at the corner.
I think both the leaks are the same source but depending on the angle the car is parked at it either pools at the inner sill or rear window corner.

I was initially thinking it was the rear window bonding but I'm not so sure.

Can it leak in where the roof rack points are?

Any ideas welcome as it's driving me to distraction.

Thanks 👍

 

[deMort]

Ok .. a wee bit of info for you ..

http://911uk.com/viewtopic.php?t=143670

Roof rail .. a very .. very rare fault .. read what i posted and see if it applies to your fault .

http://911uk.com/viewtopic.php?t=143389

General areas for water leaks .

Ok to your issue .. rear glass .. roof bar or side window i feel ..

Some images below of a poor repair i found on a Targa but same basic design .. its one possibility .. rear screen being another but if the water is getting into the chamber where the seat belt sits then i'm leaning towards the side window ..

water should in no way get into that area .

 

[RoddyC4S]

Once again, thanks Demort.

I forgot to mention that the rear passenger seat cushion was soaking wet and this is what led me to all this leaking in the 1st place.
I stripped the whole rear interior out and found pools of water lying under the 2 silver plates that hold the Bose wiring etc.
I then waited for a rain fall and where I clearly seen fast dripping water coming in from the rear passenger corner near the rear light grommet, it was dripping off a wiring loom that heads in the direction of the wiper, but the structure gap was to tight for me to see anything after that.
Now annoyingly the leak seems to be intermittent and on the last 2 rain falls not a drop has came in from that corner, but water still has went into the seat belt space section.
Looking through the info you posted I noticed a lad saying his rear seat was soaking and he traced it to the rear wiper.
Would water leaking in from there still find it's way to the seat belt void area? ... and could the leak be intermittent?
How do you repair this possible wiper leak?

Yesterday I soaked the car and the only water that came was in the seat belt section. But I know for a fact it will leak at the rear corner aswell, I've seen it doing it, badly.

I'm going to check that B post rivet you have mentioned.


Thanks for you help 👍

 

[RoddyC4S]

Ok.
Today's findings.

The water coming into the seat belt void area is coming in through a gap on the damaged passenger side skirt.
Still not sure why it would still get into the car though?? .... but regarding the seat belt void that's definitely where it's getting in from.

 

[RoddyC4S]

Damaged side skirt

 

[deMort]

Ok.
Today's findings.

The water coming into the seat belt void area is coming in through a gap on the damaged passenger side skirt.
Still not sure why it would still get into the car though?? .... but regarding the seat belt void that's definitely where it's getting in from.

Im afraid thats a new one on me .. there are fixings that hold that in place but if the leak is when stationary i can only assume one has ripped out and left a hole .

My guess would be the rear window where the rivets are and running down if it turns out to not be this ... as per my previous images .

You also have X2 leaks with i expect the rear wiper being the other ..

Remove the wiper arm .. remove the grommet .. clean it all out ans seal the grommet with plenty of silicone sealant ..

Post here about it on 997 but they have a different grommet .

http://911uk.com/viewtopic.php?t=144211

If possible can you take a photo of the area at the rear where its leaking .. using paint put an arrow to direct me to the location .

 

[RoddyC4S]

Hi Demort

Just read through the links you put up, many thanks 👍
Seems like it could be the rear wiper, but now it's stopped leaking! .... it's been out in the storms for the last few weeks and not a single drop! 🤔
On your photo with your hand in the water (on the other link) that's exactly where mine was pooling up on the n/s/r. The foam is black which tells me it's been a long term leak.
I'll investigate the rear wiper 👍

I've put some photos up showing where the leak is coming in from, it appears to be running along the loom behind the frame structure.


I'm still investigating the 2 leak down at the rear sill on the n/s/r.
I've removed the rear part of the side skirt and 2 of the upright rubber grommets that run along the length of the sill were not in place properly, it's only the 2 rear ones that were dislodged, so I'm guessing water would run down the outside of the rear wing, then find its way in between the wing and the skirt where the grommet holes were exposed and due to the angle the water would run in to the sill inside the car, now if the inner box sill section has factory holes along its length then this water may pass through these holes into the cabin floor carpet .... I'm just guessing here.
I have refitted these 2 upright grommets and silicon sealed them, I'm waiting for the silicon to dry before I water test.
As I'm sure you know there is also a rubber grommet at the rear .... at the front of the wheel tub .... which may also have dried out and is letting water into the sill inner section, I'll find out when I do the water test tomorrow.
I can't see any corrosion, I know the rear part of the sill can corrode but mine looks fairly decent, so I'm hoping these grommets are the cause.

 

[RoddyC4S]

Stand off view ...

 

[RoddyC4S]

Leak No2.

The dislodged rubber grommet on the n/s/r sill.
I'm guessing water would run down the wing, work it's way the between the wing and skirt then into the holes and into the inner sill box section.
Could this water then find its way into the cabin front section carpet from here?

 

[RoddyC4S]

Photo showing rubber grommets silicone sealed back in place.


Photo is upside down.

 

[deMort]

Ok .. that's a new leak on me i'm afraid ..

Image below of yours i've added an arrow .. water cannot flow upwards so is it possible it's running down to that point and entering the car ?

This would mean the leak is from higher up .


Wheel arch grommet .. from memory again it's far too low for this issue and again i've never had an issue with one .. anything is possible though .

The sill " grommet " thats to locate the outer sill cover .. if missing you would have a hole but its under the cover .. not much chance for water to get in there and it would be in the sill .. to get water into the car there would have to be a lot of water and at the front of the sill is an air duct .. it would run out of there i'm guessing .

if you remove the seat belt then you can see into that area .

best test is a hose pipe over the rear end for at least 10 mins to find a leak .

I am currently intrigued by this leak and have studied the images for a while but am still at a loss here

 

[RoddyC4S]

Regarding the rubber sill grommet leak, these grommets are located above the sill. The water was finding its was past the side skirt join then finding it's way past the dislodged sill grommet, the adjacent rubber sill grommet was loose aswell and letting in water.
I spent hours testing. I removed the last 2 rear grommets and then poured water down the outside of the wing, the water would follow the lower wing contour and then found its way past the side skirt where it meets the wing then because the lower wing (hidden by the skirt) is at an angle the water easily finds its way into the car via the grommet hole where it can be seen from inside the car looking in and down from the front seat belt anchor point.
I used silicon seal and attached the grommets back in place, left to cure for 24 hours then retested and it was perfect, no leaks in that point.
I believe the original glue that held these grommets in place is dried out and the slightly touch of these grommets knocks and dislodges them then the water gets in from then on.
Also I found it far better putting the grommets back in place by partially removing the side skirt and getting access that way, trying to get your arm down from the inside and getting the grommets in place is a nightmare.

Regarding the leak from the rear window, what would your guess be, the window bonding failing?

I've had a small bore scope up and in every gap and crevice in the framework when it was actually leaking and I annoyingly couldn't see a drop of water running down.
Also annoyingly in the last few heavy rain falls it's not leaked once!!! And the car is parked in the same spot.


I've attached a photo of the rear sill grommets in location for reference, taken from the seat belt anchor point.

Your help is being appreciated 👍

 

[RoddyC4S]

Photo showing water being poured down side of the outer wing, then finding its way in between the skirt and then into the rubber sill grommet hole.

 

[deMort]

Yup you have proved me wrong there .. water can get into the sill via that grommet .. i really didn't think it would but yup it can .

Its not the problem you have though , a good fix but there would need to be an awful lot of water in there to fill it to a lvl it can drain into the car .

991 and yes it's an issue in that area but for a different reason .

rear screen area .. that's the main issue which rather annoyingly has stopped .. for a water leak you can mask off areas then retest .. if it stops you know the masked area is the issue .

I've added comments to your image ..

basically is there wiring behind that " hole " that the water is leaking out from ?

On a Targa then the high lvl brake light wiring comes though in a similar area .. i'm unsure on a coupe but if wiring enters the car then it must have a grommet to seal it .. just wondering if this is an issue .

rear screen atm seems unlikely .. possible but the water has to get on the inside of that " hole " .. i don't think it can from a screen leak as the inside edge is the only place it can leak .

Whilst i dont think this is the issue im throwing it out there anyways .. for my car the water was at the top of the C pillar and not where yours is ..

http://911uk.com/viewtopic.php?t=143670

its a one off issue which atm strikes me as what yours is .

Dam shame your no where near me .. faults like this i enjoy and would happily spend several hours of a week end working on to try and figure it out .. Once you know of an issue it adds to your ability to fix future issues and makes it far cheaper for the customer .

I think at work i would be rigging up a hose pipe over the rear screen then leaving it for a couple of hours ,, if water then you try to find the highest point its wet .

In short though i cant help very much other than offer advise

 

[RoddyC4S]

Sorry Demort, maybe just my wording but the leak in the sill area was a separate leak altogether and sorry I made it sound like it was associated with the rear window for leak. It was when I was stripping the rear interior out that I just stumbled upon the sill water, there wasn't much in the sill section but a leak all the same.

Reference the rear window leak, I did think there was a wiring loom there but now I'm not so sure, it's very tight but I just think it's expanding foam insulation, the other side is exactly the same.
Yes there is a middle rear brake light grommet which is visible
And I couldn't see water coming in from there, I also took out the wiper grommet and resealed it although it did look ok.
I have had a hose over the car several for long periods and nothing, it's damn annoying, i can't put the Interior back in until this is sorted.

Would water getting in from the roof rack mounting point be a cause? ... I have poured water down here aswell though.


Thanks again 👍