You have a 2002 grand caravan sport it has started losing water since July you added 9 liters of water and cannot find the source of water loss?
==Suggestion== I have read that the newer caravans have a
problem with the rear air conditioning hoses eroding and leaking,
you might check this out, if this is the problem the dealer will
fix it for free. I have had this problem in a different type of
vehicle, found the water was slowly leaking into a cylinder and
going out the exhaust pipe,the leak was slow enough that it really
didn't effect performance. Finally started leaking enough that
steam constantly came out the tailpipe.