HaVE THEY ever FOUND THE PROBLEM why these CAMRYS are overheating

with the age of the car, I would assume your water pump seal failed, and since your car has the 3vz, it is likely that the water pump failed- those motors require specific service intervals, however it is a very good idea to replace peripheral items like, water pumps every 15 years, as a preventative maintenance- and since you have to change the timing belt every 5-6 years anyway, changing the water pump every third timing belt isn't a bad idea.

Thank you , we bought the car 2 years ago for the grandson to drive for work supposedly a LOL owned the car and it had 43,000 miles on it at the time ( per CarFax ) 85,000 now and it started loosing coolant every other day filling expansion tank and radiator (overheating). Motor runs smooth and no coolant from exhaust, SO thank you very much for the start in the right direction I hope because it is a very nice clean car ( radiator & caps and thermostat have been changed also, Thank you again very much appreciated )

Could be the water pump, but with no external leaks it could also be a head gasket. Have it pressure tested to see if the water pump leaks and leaves a puddle. A small amount of coolant might not be noticed going out the exhaust.