Frost on the *inside* of windscreen?

[buze]

This morning I was planning to take the little car out regardless of the weather (-2.5C here) but gave up when I realized the inside of the windscreen was frosted over.

I do had the impression that my car is nice and dry -- but am I wrong? could there be moisture trapped somewhere? Or is it a common problem?

 

[Lee]

Morning Buze, I would say there is some moisture inside, weather there's a leak or something else have a look at the carpets just in front of the seats, you can slightly peal it back and see if there's any water. I leave a small moisture trap in Sam's zed to collect any moisture that may build up inside. The car was soaked inside when we bought it so it's taken a while to get totally dry.

 

[GazHyde]

Most likely water in the thick foam under the seats, only way to find out is to lift the carpet up and squeeze the foam! My last Z3 was always dry and never frosted on the inside.

 

[buze]

Morning guys -- I'll have to have a look. Worst case I have a pretty powerful dehumidifier I could just put in the car for a while. Extracts 5L of water from the air in ~12H or so... that would do the job!
Car has hardtop on too, so that should prevent any more water getting in anyway...

 

[GazHyde]

I used to borrow a dehumidifier and balance it on the centre console and leave it running every few months. Never pulled much out, so was more of a comfort to know there isn't any damp!

 

[Stevo7682]

My Dakar sits outside has never froze on inside.
Lynne's turquoise green zed had major roof damage at rear window so expected a bit of damp. ( took 3 weeks to dry the carpets after removing ) the front section of the carpet was dry to touch the rear carpet under the seat was damp on top .
After removed the foam insulation underneath couldn't have absorbed any more water if it tried absolutely soaking after removed still left about 2 litres of water swimming about each floorpan you would be shocked at just how much can hide under the carpet.

 

[hard top]

2 litres of water swimming about each floorpan

There are rubber bungs in the floor.

 

[Stevo7682]

There are rubber bungs in the floor.

All dried up now

 

[buze]

I've discovered yesterday that the water in the car comes from... the hardtop! The seal between the top, the window, and the top of the car frame (on passenger side) is not perfect it seems. I've tried re-adjusting it but I don't know if that will be sufficient...
The rubber seems all OK all around, but the two shaped rubber bits don't have the exact same shape, and that joint seems to be letting water in...

 

[Nodzed]

When you adjusted it did you slacken all four mounting points?

 

[Jjim]

I've discovered yesterday that the water in the car comes from... the hardtop! The seal between the top, the window, and the top of the car frame (on passenger side) is not perfect it seems. I've tried re-adjusting it but I don't know if that will be sufficient...
The rubber seems all OK all around, but the two shaped rubber bits don't have the exact same shape, and that joint seems to be letting water in...

You’ll find that it’s most likely a rubber ‘bung’ part at the top of the A pillar that is most likely the cause of the water ingress into the car.



To get to this you need to remove the hardtop.

The picture shows how the water gets in. The rubber bung should be sealed. 2 options, either buy a new seal or get some sealer to seal the bung back in.

 

[buze]

BTW , I have checked the plugs and they are sound. It's definitely linked to that rubber 'contact' joint there. Tried earlier to pour water over it and sure enough, it gets inside due to the offset. Not sure any adjustment of the hard top will help there!

 

[Ianmc]

Always use the aircon, even in the winter. It's good for the aircon system and the car.

 

[hard top]

Always use the aircon

I did not have it on my Z but I did on my Merc's and as you say, always used it all year round, great for steamed up windows.

 

[Piperbill]

Just a little follow up. I didn't have frost (not cold enough here) but last winter all the insides of my windows were wet in the morning and the carpet was getting soaked. I have a coupe, so no hardtop leaks. It turned out to be that the door card plastic protective sheeting (inside each door) was totally shot and the moisture was coming in from there. I had the cards restored with new plastic and everything seems fine now. Just a little FYI.

 

[t-tony]

Just a little follow up. I didn't have frost (not cold enough here) but last winter all the insides of my windows were wet in the morning and the carpet was getting soaked. I have a coupe, so no hardtop leaks. It turned out to be that the door card plastic protective sheeting (inside each door) was totally shot and the moisture was coming in from there. I had the cards restored with new plastic and everything seems fine now. Just a little FYI.

Good info @Piperbill , thanks for posting.

Tony.