2001 Dodge Caravan fluid loss

Sudden onset intermittent collent loss. VAn was suddenly low on water. But never got very hot maybe just a touch over normal. Filled it. Parked on a slab and left idle to check for leaks, nothing. Drove for about a week with no loss then suddenly gone again. Filled it again and let it sit without driving a week. Level was down again. Filled it and drove with no loss about 30 miles. This ia all cool to cold weather driving. Have heard these are bad about water pumps weeping etc. Also possible head gasket. Do you have any ideas on problem or reapir costs? Its been very good with almost no prblems. Just a belt replaced etc, We did get water in fuel apx 6mo ago and had it drained at local shop. They said there was no fuel filter to replace. Dont know if this would cause problems or not. Thanks very much