I know that this has been asked before, but why does it occur?
I have and still do own an old car and I have never been troubled with this problem before, it has been suggested that the metal of the boot lid is thin, which it certainly is, but then so is my 1970 MG Midget and that stays bone dry
Is it anything to do with the battery being in the boot, mine is an ordinary lead acid, but it is sealed and vented, does any one have the pucka battery fitted and do you get the condensation? I used to own a Riley Elf (posh Mini) with a boot mounted battery and this was always dry, so I am at a loss.
It is dry in the summer and wet in the winter unsurprisingly, and appears to make no difference as to if it is driven or not. I can understand that when driven the exhaust box is under the boot floor and the air in the boot gets warm, I have replaced the heat shield and this still makes no difference. It has just stood for 5 weeks with the battery disconnected and upon my return was running in water. I am at a loss as to the cause and why it is a problem with this car.
I have tried the silica gel pack and yes it is better as long as you remember to keep replacing it and I am now considering fitting a panel to the inside of the lid with some form of sealed cell plastic insulation behind it.
Significant condensation on the bootlid is indicative of water in the car. If the car is dry you will not get dripping condensation in the boot. If the car has moisture in it the first place it condenses is the bootlid.
Make sure the drains behind the seat are clear and no leaks from the rainrail, porosity of the softtop, etc.
If the battery is of the sealed gel type, and vented as you say, then it can’t cause condensation. A non vented normal lead acid will cause some sulfation damage however, around the battery area. So, have you checked the boot lid for leaks? You say it was running this time, that sounds like a leak, not just condensation. Heat, followed by cold, can introduce condensation in an enclosed area, but it’s not normal, so I would say you need to look for possible other causes.
Now I’m retired, the car get’s used about twice a week on average, but no condensation (ever) inside the boot. The car is permanently parked on the drive, where I could expect weather conditions to affect it, but none has.
Thanks all, no the car lives on the drive.
It has got a leaking rain rail which I am about to replace and to be honest I had not thought about this being a source of moisture in the boot. The rear light seals are newish, and the boot lid seal is ok, so hopefully when the rain rail is replaced all should be fine and dry.
Thanks again for the info.
That should cure it, I would check your high level brake light also, mine used to have a wet boot and found the rubber seal around the light to have gone brittle and leaking made a new seal and all is good.
I used some 6mm round soft rubber we used on CNC suction pods at work, just cut a piece to length glued the ends together and pushed it into the slot, bolted the light back in and it can now take a good jet washing.
Thanks to all, new 2nd hand rain rail now fitted and it has not stopped raining since. Car appears to be dry and condensation has disappeared from the boot. So far so good. Again many thanks to all who offered advice.