Water collecting in boot/rear seat area. Any help greatly appreciated!

[harveyxsmith]

Evening guys,

Really hoping someone out there has had the same issue and managed to resolve it.

I have an ongoing leak at the rear of the car, on the corner where the top of the taillight meets the boot. I’ve searched every forum I can, siliconed the boot stops, checked any cracks on the spot welds, siliconed them, taken the trim off on the side/rear of the roof (not sure what it’s called) re-sealed the spoiler and I just cannot for the life of me work out where it is getting in. It’s almost like it’s inbetween the inner/outer skin of the car? It’s getting rather annoying as everything, headlining etc is bone dry and I can’t put my cage/false floor in whilst it continues to leak.


I’ll put some photos below of where it’s getting in. If anyone can give any pointers, will be greatly appreciated. Cheers.

 

[harveyxsmith]

might be worth mentioning, from inside the car, we cannot see it leaking any higher up than where the tissue is in the photos. But, it does seem to leak in when pouring water over the centre of the car in the panel gap where the boot meets roof.

 

[MarcB]

It could be one of two things.

The rubber grommet that sits next to the rear light cluster as that's a common fault or the rear light might not be sealing correctly and in its correct position.

 

[harveyxsmith]

It could be one of two things.

The rubber grommet that sits next to the rear light cluster as that's a common fault or the rear light might not be sealing correctly and in its correct position.

Thanks for the response Marc. I’ve already sealed the boot stops, and re-fitted the rear light a couple times. But where the water is getting in is a good 2-4” higher up the car than the boot stops/hole for the light connectors.

 

[Une_Baguette]

I've the exact same issue on 4 of my Clio's and can't for the life me figure it out. I believe it's one of the spot welds somewhere around that area and I've heard other people having similar issues it must be becoming a more common issue with age I believe. Boot grommets are sealed on all of mine as well.

 

[TC.]

Yep one of mine has a leaky boot, sealed the grommets and fitted a different set of rear lights. Not a clue where it’s getting in.

 

[TheBandit]

Might have an issue like this on one of mine... Leaving a comment to stay in the loop

 

[Darren S]

I had very similar on the driver's side at the rear. Leaking in, ever so slightly when there was driving rain - collecting in and around where the jack is usually stored at the back corner.

Like yourself, took loads of trim out, silicone'd areas - but it still came in. Turned out that there was the tiniest of gaps in the skin, beneath the plastic strip where the roof-rack attaches. Got that addressed at a body-shop and it's never leaked in since. I cleaned the above with a slightly abrasive brush and then POR-15'd the s**t out of that boot area and under the rear bench.

I do however, have a small leak on the nearside rear under the bench seat too. That appears to be coming through one of the bolts through the floor, potentially.

 

[harveyxsmith]

UPDATE - I believe I’ve now resolved my leak. I ran the hose up the side of the car starting low and working my way up until it began leaking. It was in fact somewhere near the roof rail, took the plastic trim off and there was a hairline crack right on the corner where the roof meets the back end of the car/top of the rear quarter. It was really difficult to see, I guess as these cars are getting older (plus me using mine on track) is causing the factory spotwelds/bonding to have cracks, lift etc. I siliconed over the crack, put the plastic trim back on, let it dry and ran the hose again and it was bone dry. However, it’s not hammered down since doing it which will be the real test. I’d imagine you guys potentially have similar ‘hairline cracks’ somewhere on your shells although they’re likely not going to be in the same place and it was a PITA to find. 🙁

 

[harveyxsmith]

UPDATE - I believe I’ve now resolved my leak. I ran the hose up the side of the car starting low and working my way up until it began leaking. It was in fact somewhere near the roof rail, took the plastic trim off and there was a hairline crack right on the corner where the roof meets the back end of the car/top of the rear quarter. It was really difficult to see, I guess as these cars are getting older (plus me using mine on track) is causing the factory spotwelds/bonding to have cracks, lift etc. I siliconed over the crack, put the plastic trim back on, let it dry and ran the hose again and it was bone dry. However, it’s not hammered down since doing it which will be the real test. I’d imagine you guys potentially have similar ‘hairline cracks’ somewhere on your shells although they’re likely not going to be in the same place and it was a PITA to find. 🙁

 

[TC.]

Must have a check on mine tomorrow 👍🏼

 

[AUS-172]

UPDATE - I believe I’ve now resolved my leak. I ran the hose up the side of the car starting low and working my way up until it began leaking. It was in fact somewhere near the roof rail, took the plastic trim off and there was a hairline crack right on the corner where the roof meets the back end of the car/top of the rear quarter. It was really difficult to see, I guess as these cars are getting older (plus me using mine on track) is causing the factory spotwelds/bonding to have cracks, lift etc. I siliconed over the crack, put the plastic trim back on, let it dry and ran the hose again and it was bone dry. However, it’s not hammered down since doing it which will be the real test. I’d imagine you guys potentially have similar ‘hairline cracks’ somewhere on your shells although they’re likely not going to be in the same place and it was a PITA to find. 🙁

Appreciate this! Just wanted to add some extra info/context/background info to this thread for anyone chasing the same leak.

I was having the same symptoms as the OP. Originally found water under the back seat (LHS). Pulled the bench out, ran the hose and found water emerging from under the back seat/boot carpet (red circle), and then tracking down into the recessed void:

Next step was to pull the boot carpets out, remove all of the rear trims and repeat the hosing process. I was surprised to then see water appearing in the bodyline above the taillight. The water was pooling in the red circle, spilling over the edge, running down past the back of the light, onto the edge of the boot floor (I have a 172 so it has a spare wheel well), and then making its way towards the rear seat. It must not be 100% flat on the boot section as the water moved towards the seat pretty quickly (car was on a flat surface):

So, then began the process of working out how it was getting behind the outer skin. It obviously wasn't going to be the 'hatch stop grommet' or the lights themselves, as the water was higher, so I began to work my way up progressively with the hose going past the spot welds, the plate that holds the bottom of the boot strut and so on. It wasn't until I wet the top of the body in the gap between the roof and the spoiler that I got water in the car again.

From there, I eliminated the aerial base and the rubber grommets for the rear wiring. Despite the common sentiment if you ask around or Google this problem, I'd be surprised if either was your culprit. The grommets mount to the external side of of an exposed double skin, and the base of the aerial is also exposed to the interior directly, so they'd be MUCH more likely to just let water drop onto your headliner as opposed to having it track down towards the taillights.

Eventually, thanks to Harvey's post above, I went over the back of the car with a magnifying glass and found a small hairline in the seam sealer at the join circled in the picture in post #10. Had a quick scrape with a steel pick and managed to remove some dead seam sealer which I guess has failed with time/water ingress:

Then, once I removed the gutter trim and looked from the top, I could see a tiny (but obvious) gap as well:

Cleared up both areas as much as I could, applied some POR15 as a precaution (even though I found no evidence of corrosion/rust), and then a fresh bead of Sikaflex 227 over the top. Sprayed some lanolin and cavity wax into the back side of the skins while I had all the trim off as well.

Job done!