I have developed similiar symptoms in my 92 Accord. Car overheated, then after cooling, while running temp gauge fluctuates, but eventually (after 5-10 mins) stays pegged on hot. First thing I did was flush the system and put a thermostat in. Still have the problem.

Car has 280k miles, a water pump/timing belt replacement will be costly if I pay someone, and a total pain for a weekend mechanic like me if I do it myself.

Any other tests before I make a drastic move?

Thanks, Spy