Subaru 2008 impreza automatic after a short drive my coolant is gone after a few hours my coolant is gone empty i have to put coolant to get from a to b what is the issue ?
You either blew a head gasket or there are. Leaks coming from the cooling system. There are no other options.
Well if your leaking coolant figure out where it’s leaking coolant, but considering it’s a Subaru, it’s probably getting coolant pushed into the cylinders from either a cracked block or a bad head gasket(s)
As others have said that vintage Subaru (OHC with timing belt) is notorious for blowing head gaskets. If that car still has its original 16-year-old gaskets there's a good chance that's the problem. If you do have a head gasket problem unless you can do the work yourself the cost of the repair likely would exceed the car's value.
However, it might be worth doing a cooling system pressure test and/or use UV dye to spot an external leak that occurs when the cooling system is pressurized.