another head gasket problem on Forester

Coolant on the floor means your cooling system is leaking, not the head gasket. Find out where it's dripping onto the floor and work backwards to find the leak.

I had looked for source without success so took it to the shop where I have service and they said pressure test showed it coming from the head gasket.

Why didn't they just check for the source of the leak? When there's a external coolant leak, there's no need to do a pressure test. You just look for the the leak. Well, that's what I'd do anyway. Things may be different in your town.

My son's WRX had such a symptom lately. He thought gasket problem, when looked into it, checking exhaust gas in coolant, white smoke form tail pipe, etc. All negative. When I checked coolant system with Stant pressure tester, there was a tiny leak. The leaked coolant dried up from engine heat by the time we check for leak visually. One of the hose had pin hole which caused temp fluctuation while driving particularly when idling at stop light. Replaced hose, added coolant, burped the system. No more issues.

I assume they saw it at the gasket point when doing pressure test.

Irregardless it is leaking somewhere. Forester is 13 years old and wife has been telling me to buy a new one. Earlier in the year, I had posted that it was getting old and leaky but that was oil, apparently around filter from grit on seal.

I did stop at the dealers yesterday to look at the new Forester and was impressed with what I saw. Told saleswoman that I would probably buy a new one at the end of winter from them via the family and friends deal.

My philosophy has been to trade the car in when cost of repairs start to approach book value. Had it happen to a friend this year who had spent $6,000 to repair his old Chevy Blazer to have it go out of commission again and only get $500 on trade in.