how does the roof seal to the body

andy6409

Member
 Stone,Staffs
I keep finding water in the o/s cubby hole in the boot so decided to investigate today

I removed the shelf and o/s mount,the carpet trim and sound proofing (which was soaked)

When I poured water on the car it came in from underneath the drain funnel and ran down the arch above the rear suspension mount collecting in the cubby hole . As far as I can work out it can only be getting in from between the roof and the body. The drains are emptying fine
I have checked the parts list and can see no obvious seal between roof and body like my old MX5 had

Can anyone tell me how it seals or how I can reseal it

Regards
andy
 
The roof fabric is connected to the body cowl by a series of spring clips. It is expected to leak. The leaks drip into a collection trough that channels the water to the drain funnels and out of the car. There should be a tube that carries the water from the funnel to within a couple inches of the car's floor pan. Water should not be appearing under the funnel and running down the arch.

Even so, I'm not sure how it gets in the boot. Maybe it gets blown up into the shock tower? That's the only hole I can think of. Another thought is maybe it's not dripping into the trough like it's supposed to, rather it runs down along the underside of the body, before eventually falling into the boot? The other common source of water in the boot is the 3rd brake light. It's either cracked or the tension spring doesn't seal it to the lid properly. You should investigate that possibility as well.
 
sounds like you may have the same problem i had last year. there is a gap between the boot lid bracket and the body that lets water run off under the car. the water then runs down the side and enters around the air vent in the cubby hole behind the carpet. if that is the issue then this thread should help you

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=32376
 
I reviewed chrisj's linked thread with interest. I somehow missed it the 1st time around. I think it's important to determine the ingress method. Most likely candidates is chrisj's vent panel or the openings behind the tail lights. It appears that the strut base is intended to drain, but if for some fluke the water gets to the vent panel, I see no problem sealing the strut base, as accessing the true cause would be difficult. Water can still drain over the tail light. I would not seal the base unless you've confirmed the vent panel is the ingress point. It's less than ideal to encourage water towards the tail light.

Ingress through the tail light openings is also possible. The only thing stopping it is a foam gasket which doesn't seem to fit that well and doesn't even look fully waterproof. Ensure this gasket is in good condition. Examine the mating surfaces for any evidence of something that could cause improper sealing. If you can confirm this is the ingress point, additional sealant may be warranted.
 
the water is definitely coming directly down from under the roof drain funnel, much higher than the vent and strut mount. It is then following a seam in the bodywork to the boot floor and then running backwards into the well below the light
From what I can see ,water should only get into the car at the front just behind the door and run straight into the funnel then down the drain
I am checking the drains again to make 100% sure they are clean and the funnel not overflowing . I tried using a 5.56mm rifle barrel brush from the top on the right side today but it would only go in a short distance so it is either blocked or the tube is a smaller diameter. I have found some 4mm steel cable which I will try tomorrow as it is stiff but flexible
 
Just bite the bullet as it were, jack the car up, remove the rear wheel then the three plastic bolts on the sill side of the wheel arch. shove your hand in and feel around until you find a rubbery grommit in the roof of the drain channel and yank it out.
Clean it up and replace into said hole, rinse and repeat for the other side, done.

andy6409 said:
the water is definitely coming directly down from under the roof drain funnel, much higher than the vent and strut mount. It is then following a seam in the bodywork to the boot floor and then running backwards into the well below the light
From what I can see ,water should only get into the car at the front just behind the door and run straight into the funnel then down the drain
I am checking the drains again to make 100% sure they are clean and the funnel not overflowing . I tried using a 5.56mm rifle barrel brush from the top on the right side today but it would only go in a short distance so it is either blocked or the tube is a smaller diameter. I have found some 4mm steel cable which I will try tomorrow as it is stiff but flexible
 
I clean my drains from the bottom with a 9mm OD plastic tube attached to my hoover. It goes all the way up the tube to the bottom of the funnel, then hits a ferrule or something and stops. I think the tube should fit the narrowed opening, it's just that it's stiffness and the feed angle cause it to catch on the edge and not progress. I find it hard to believe there would intentionally be a restriction less than 5.5mm diameter just below the funnel bottom. Something's not right. And the real question is what's happening on the o/s? You can only access that side from the bottom.
 
the only way to be sure is to get someone small enough to climb in the boot/trunk with a torch then pour a large amount of water over the body. you will never be sure otherwise
 
Update

Decided to ease my mind and check the roof drains again

o/s being the drivers (RH) side you can access from the top

I used a piece of rigid tube to guide a thin flexible steel cable to the top of the drain tube the slowly pushed it down until it met resistance then twisted and pushed at the same time until it came out of the bottom then follwed this with a thicker piece of cable
when I checked under the drain hole there was a small y shaped twig there that must have been partially blocking the drain tube causing it to overflow into the boot in heavy rain

I measured the length the cable had gone all the way through,marked it then did the same from the bottom on the other side and this went straight through past the mark with no resistance at all :D
 
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