Could be water pump [headgasket if water level goes down and more dripping moisture from end of exhaust] based on old vehicles i've had. Also you've got your question in caravans and motor homes section car/vans further along catagory line.,
bb.
January 2011
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix caravans/motorhomes.