Dave928S

I parked my GTS on a slight uphill incline (nose up) with a slight crossfall to the right side, while it was raining. I've not had any leaks until now, and there is no evidence of there ever being one before.

I just put on a new plenum cover, so water can only get in at each end, and I cleaned everything out before putting it on. The drain is clean. CE panel area is dry and footwell on the left side is dry.

I can't see where the water is coming from exactly,but it's dribbling along under the carpet in the outermost groove/depression in the floor and ends up in the footwell behind the drivers seat (right hand side). It's only leaked about a cup full of water into the cabin in the last 48 hours or so.

I've mopped up the small amount of water and it's not raining, but the slow leak is still there. I took off the plenum cover, and over on the far right side underneath the back of the right fender I can see a small puddle of water, which is sitting there because of the nose up and slope to the right side attitude of the car. As it's still slowly dribbling in, this must be where it's coming from, but without taking the fender off or removing interior insulation I can't see exactly where it's leaking in.

Does anyone have any idea how it could be getting through there? I can't see any penetrations in that area from the limited view I can get, but I'm thinking it might be a small defect in the seam seal maybe?

Does anyone have a pic of that area so I can get a better idea of what the issue might be?

Maybe all the other clues are leading me in the wrong direction and it's getting in somewhere else.

Any ideas appreciated.

Leon Speed

If all things are upside-down or reversed in Australia, how about this? http://www.billsworkshop.com/P928S4/Tip001.htm
Sorry, not familiar with RHD.

Dave928S

Thanks Aryan ... I'll check and see if I have that hole. I've got a few endoscopes that I'll use to have a look tomorrow. I have the wiper motor on the right side of the car, and the leak seems to originate from the area behind the hinge with the puddle of water, under the rear of that fender. It seems that RHD is a mirror image and so my symptoms are almost the same, but it's not dripping directly from above. I can't feel any wet areas up above the tray.

WallyP

If a small amount of water in the bottom still leaks into the car, perhaps a simple fix is in order.

Let the plenum area dry completely, then pour in a liquid that will cure in the bottom, sealing the leak.

Dave928S

Thanks ... good thought Wally. If it is a seam seal leak and I can see the spot with an endoscope I could flood that area with a little two pot resin from a syringe with a tube on it, with the car parked in the same area so it finds the same leak spot. It's still got me beat why its never leaked before.

The water comes from somewhere to the outside of the accelerator pedal, behind the carpet and hood release, and flows back along the floor groove.

Hilton

Dave - I had a leak like you describe on one of my cars. The seam sealing had failed on the steel frame under the right-front wing - after removing the wiper arms, cowl and wiper motor, I could see where it had failed and the weld had rusted through.

The water was entering the driver's footwell from behind the bracket where the accelerator pedal attaches - easily reproduced with a cup of water, a funnel and a short length of hose to direct water to where it had failed.

With the wiper motor and arms removed, you can reach in there with a forearm - so I wire brushed it, painted with rust converter, and then sealed it with a neutral-cure silicone (i.e. non acidic so it wouldn't cause further corrosion). The driver's carpet is still dry and we've had about 150mm of rain in the last 3 days - the car is parked outside.

I think a factor which contributed to failure was dirt and leaf debris blocking the channel at the front, in that space under the wing - there's a channel where its meant to drain down into the bulkhead behind the firewall, and across to the rubber flap on the passenger side. The channel was blocked with leaf mulch and so water was sitting in there.

Dave928S

Hi Hilton .... I just saw your reply. Thanks so much, I'll check that out and report back.

Dave928S

I've checked every area of the plenum and its totally clean and corrosion free . I used a couple of high powered bright endoscopes which have super bright halogen mini globes on the end. The water I was seeing on the right side under the rear of the wing led me to believe it was getting in there because a puddle was sitting in that area and it was still leaking in ... but it was fine.

I've checked every inch of the seams and all the penetrations and there's no chance water is getting in from the plenum.

I'm now convinced it's the left sunroof drain tube, or maybe both, as the left one is almost totally blocked and I can replicate the leak that I got before into the cabin when I overload the front tubes with water.

I've got another thread running that I'll update when I figure out what's going on.

Thanks to those who helped with suggestions.