is it possible that a thermostat gets stuck closed, then once taken out of the car it tests fine? Having some cooling issues and I tested the thermostat and it opened fine. I am guessing now that it is the water pump but my car has only 18k miles on it, granted it is a little over 3 years old.

Symptoms are car overheats, does not cool down at speed, cool air from heater even after car is warmed up, top rad hose hot, bottom one just after thermostat is cool. I burped the system and made sure the coolant was full.

^ i have the actually same issue, but still havent figured it out yet. brought into a shop yesterday. hope they can figure it out ....but keep posted please..!!!
plz let me know if u figure out something

is it possible that a thermostat gets stuck closed, then once taken out of the car it tests fine?

thermostats are $3... never put an old one back in.

I put the new one in this am vs the old one and it worked. Funny that the old one opened in hot water, but your right for as cheap as they are it was worth the try.

^ did u figure it out yet?

The old thermostat was just stuck closed.