Progress on my soundproofing/sound system refit was halted by a water leak into the front passenger footwell The carpet is out, exposing the bare floor, and I noticed that after days parked in heavy rain, there was a few mm depth of water along the side of the floor, all the way back to the seat crossmember.

When I removed the carpet several days ago, it was dry, and I hadn't noticed any wet footwell/misting up problems in the last few months, so this was a minor water leak. But I knew it would need fixing. Particularly as I have added polyurethane expanding foam to the bottom of the front pillars - I don't want it getting wet... it was all quite depressing. And no, there are no drain holes in the bottom of that pillar (I checked). Water is not supposed to be in there and I would probably never have noticed if I hadn't left the car parked outside with the carpets removed.

I spent a while poking around with a torch and hosing water into the front scuttle/heater chamber area, and at one time, I managed to get a trickle of water coming out of the front pillar (the one that has the door hinges). But since there was now water everywhere, I wasn't certain where the water was getting in - only that it was getting into the pillar and then running out into the floor. I dried the floor and tried hosing all sorts of places separately, including the gaps around the front-left wing and even the sides of the roof and windscreen. The floor stayed dry.

I found this in a Google search: http://www.fiat500owners.com/forum/...orum/1296-water-infiltration-3.html#post10199

So I removed the wipers and the panel under the wipers (lost one of the front three clips and broke another one - the centre part is supposed to unscrew, but it didn't ), and then I spotted a poorly-sealed seam behind the bonnet hinge, left side. This is a terrible area to try and photograph, as it is obscured by the hinge, but if you see the unsealed seam in the red circle below, and imagine that extended forward behind the hinge, that's the area that lets the water in.

After checking the floor was still dry, I hosed water just into that seam. Bingo, a significant puddle quickly appeared on the floor. What satisfaction!

Of course, that might not be the only place that water gets into that pillar, but it seems the most likely, especially as someone else had the same problem and sealing it was the solution in the end (though no-one was particularly happy about that solution). I expect water runs down the bonnet hinge, particularly when the bonnet is shut.

It seems that area under the windscreen is a tricky spot for water control, as it pours through the plastic trim and literally goes everywhere - such as all over the suspension mounts (as we know already...)

To fix this properly, I shall remove the bonnet (pity I'll have to crack the paint on the nuts) and then the left bonnet hinge, so that the untidy sealant can be dug out and re-done in a tidy fashion (unlike for the Canadian customer). I'll use a polyurethane sealant. First I have to wait for everything to dry out... it looks like we shall get a couple of sunny days, so I hope to get over this hurdle on Friday. I thought about doing the right-side hinge too, but I suppose it's best not to fix what isn't broken...

Anyway - hopefully this might help someone else trying to find a water leak into the footwell...

-Alex

Blimey Alex!

Your car is going to be the best built 500 ever..

I'm always rather alarmed when I poke closely around new cars... I think build quality has got worse over the years as materials quality has improved.

They can afford to let a bit of water in, since the metal won't dissolve in 5 minutes flat any more... but for an owner of plenty of "not-yet-classic" Fiat and Alfas, I've become used to solving the problems that just $1 worth of additional mastic would have completely prevented...

Does your 500 have paint under the bonnet? I've seen a few where it's just more or less primer... Guess what my first job when I buy a 500 is going to be (after sealing the hinge seam, obviously?)

Ralf S.

Thanks Ralf!

Yes, I think we have to remember that the 500 is quite well made but it IS only a cheap, small car. The sealing of some body seams is a bit haphazard (the side of my floor shows a few stops-and-starts in the mastic smearing) and there's not a lot of paint in the seams at the back of the engine bay, under the windscreen. I could have been imagining things but I thought I saw that familiar orange colour starting in there. We don't know which parts are galvanised yet - but I doubt it's as galvanised as a Tipo was.

Remember when 156 floors started rusting out in England? Quite a surprise... and still no rusty 156s here.

Meanwhile - good news - yesterday I sealed my seams and it's rained almost constantly since, and NO water in my footwell now, so I'm a happy bunny and ready to carry on with my sound-deadening/trim reinstall.

Still can't show it very well in a photo - the culprit was the small horizontal seam running back from the hinge to the bulkhead, which originally had no sealant at all. As you can see, I removed and sealed around the bonnet hinge as well, and smoothed out the other sealed seams in that area, going across under the windscreen too (not shown here). I removed the bonnet, which meant cracking the paint on the bonnet nuts, but it was worth it to get proper access.

I used white Sikaflex made-in-Japan overpaintable polyurethane sealant intended for this application. I used a great number of paper towels cleaning up with mineral turpentine - a protruding big fat bead may look more OEM, but I decided a minimalist approach is better - less likely to trap water or crack and fall off.

I will wisp some blue over this with an airbrush at some stage as I know the white looks ugly, but thought it best to solve the problem first and worry about appearance after that

-Alex