Toyota Repair: temp gauge, coolant water, radiator hose

Question
i have a 6 cylinder 94 toyota pick up and my temp gauge goes all the way up and comes back down when the engine is hot and b4 it wouldnt do that it will go up but not past the middle. Ive been told i need to purge the cooling system?  

Answer
Bill,

Sorry if this got answered twice, my computer froze up on me. anyway it sounds to me that you have a sticking thermostat.  On the 6 cylinder engines it is located in the lower radiator hose on the engine. Three bolts hold it on. drain the coolant and pull the housing off & remove the thermostat. Be sure when you install the new one that the spring is facing in towards the engine. I also try to set the air bleeder up.  fill it with coolant/water mix and start the engine. Let it warm up enough to open the thermostat and purge all the air out. top it off and put the cap back on.