95 trep cooling issues...really getting on my nerves

ok...this is my first dodge ive owned..been reading the threads now for a few days and there seems to be alot of knowlegable people here. heres my problem...i have 95 with the 3.5 just replaced thermostat,water pump,timingbelt,tentioner,tranny cooler(i broke it during re-install....ooops) car will run in normal perameters for 15-20 mins then the the temp climbs real fast i immediatly pull over before temp hits red. coolant comes boiling out the over flow...fans not coming on fuse is good getting ready to replace coolant temp sensor and fan relays..my chiltons manual says if the coolant sensor is bad the check engine light will come on and car will go into limp mode.thats not happening so im not too sure that the temp sensor is suspect.possible system needs bled more/again?this is not my first rodeo...been working on cars/trucks all my life and this car is just making me crazy...my reading tells me the 3.5 is the better of engine that chrysler makes for these cars.any suggestions???
:banghead::banghead::banghead:

This car is notorious for air trapped in cooling system. Should have a bleeder in the thermostat hsg. If not you can remove the coolant sensor to bleed.Sensor needs to be immersed in liquid not air or steam. Try bleeding air;run a few minutes and rebleed. Good Luck

thanks got it handled i think new cap,temp sensor,fans running now....re bled seems to be alright now thank you