Technical Possible solution to persistent water leak?

[RoyBGood]

My wife's 2002 Punto has a mystery rainwater leak that regularly manifests itself on the driver's mat and the wiring loom above it. We were looking closely at the scuttle today and noticed a patched area made of a mystery black substance approx. 2mm thick which is waterlogged and breaking up with age. This patch is directly above where rainwater collects. As the patch is on the lowest point of the scuttle, we wondered if it was covering up pre-formed holes that aren't used in this model - is this a correct guess? That being the case, I'm hoping that removing the patch and replacing it with a piece of material that's properly waterproof might cure the problem. The photo is taken with the camera's left edge almost touching the bottom of the scuttle, pointing towards the driver's side. The patching shown is almost hidden by the wiper motor when looking from above. Any helpful comments appreciated.

 

[J4MALD1N]

Hmm, water coming in on one side behind the dash is a good indicator that the water is coming in from the windshield drain area. Looking at that photo, it seems water settles there quite often which can make its way into the car. Are the drain holes all clear?

Those patches don't seem to be looking very happy however I've a feeling they're patching up something. It could just be sound deadening but to be on the safe side, I'd highly recommend peeling all that up to check and repatch if needed. Wont be a very fun job but with the scuttle removed and wiper linkage out, would make loads more room. Since water is getting in to the car, it can cause electrical issues so would be advisable to sort that issue as soon as possible.

I did find a photo from my MK2 and took a snapshot from a video. As you can see that patch thing is nowhere to be seen except in the centre on the vertical part away from the water.

All the best!

 

[varesecrazy]

Is the material similar to the factory fitted floor liner.. that tends to craze with age
blu73 has swapped that stuff out before I believe

 

[RoyBGood]

Well I removed the mystery material, which didn't take a lot of effort as it was falling to bits anyway. There were two layers in places and both were waterlogged. I had hoped to reveal unused holes for parts not used on this model, which would've explained the leak. Part of the material covered what may be a production weld? Can they become porous to water if not done properly? I noted that some of the silicone sealer around the adjacent drain nozzle had perished, so will renew that today.

 

[RoyBGood]

Hmm, water coming in on one side behind the dash is a good indicator that the water is coming in from the windshield drain area. Looking at that photo, it seems water settles there quite often which can make its way into the car. Are the drain holes all clear?

Those patches don't seem to be looking very happy however I've a feeling they're patching up something. It could just be sound deadening but to be on the safe side, I'd highly recommend peeling all that up to check and repatch if needed. Wont be a very fun job but with the scuttle removed and wiper linkage out, would make loads more room. Since water is getting in to the car, it can cause electrical issues so would be advisable to sort that issue as soon as possible.

I did find a photo from my MK2 and took a snapshot from a video. As you can see that patch thing is nowhere to be seen except in the centre on the vertical part away from the water.

All the best!

Thanks for your reply. Yes, drain holes are clear - I do this job regularly. The shape of the material is odd - like it's an offcut / scrap of something used elsewhere. The thickness of the two layers - approx. 2mm was actually compromising the rainwater flow to the drain holes and just sat there, soaking into the mystery material.

 

[J4MALD1N]

If it was compromising the water drainage then it definitely wasn't from factory. Replace and/or repair anything that is visibly damaged and pour some water down the windscreen. Also pour some over small (suspicious) areas and see if water makes it into the car. Try narrow it down to a specific area

I can only assume someone put some sound deadening there to reduce the noise from the wiper motor judging by how it's on one side only and 2mm thick. No other reason why it would be there other than an attempt to patch up a hole.

If there is no signs of water entering the car then you likely fixed the issue by removing the material however to double check, hose the front and sides of the car and see if water is getting in. May as well give the car a little bath at that point too

 

[judderbar]

I had a look on my car. It is hard to see how ordinary rain can cause a problem via the scuttle unless the soundproofing felt is taking the water from the bottom of the scuttle rearwards into a hole in the firewall. On the gearbox side the felt goes in front of the duckbill. On the engine side the felt is a long way away from interfering with the duckbill.