Two problems related to vehicle overheat have been reported for the 1998 Subaru Outback. The most recently reported issues are listed below.
While driving vehicle overheated. This happened three times. When taken to get serviced the third time it was determined that it was due to the head gasket.
Car overheated. Towed to garage. They replaced thermostat and tested. Ran ok for about 20 miles. Overheated again. Towed to garage. Now the diagnosis is that I need a new head gasket. This car has less than 90,000 miles and has been maintained flawlessly.