well, all started when i needed a new water pump cause the gasket was pushed out and leaking, and at the time the truck was running 195F. took the truck in for a new water pump, got it back and i noticed right away the temp went right up to 200F and stayed there. u can tell when the thermostat opened up cause the temp would drop when go back up to where is was at 200. well i thought this was odd cause it always ran at 195. well i noticed when i go up a little hill it hits 205F and when im off the gas it drops back down to 195-198F. relgular driving on flat roads it hovers around 200. Now this is going on for about over 3 months now and still can not figure out whats wrong. Truck is taking anti-freeze out of the over flow but can not figure out where it is going. the truck is dry underneath. The other day it hit 215F going up the mountain at half throttle bout 55mph but there was alittle puddle of anti-freeze on the drivers side frame under the radiator. havent seen that since. i have to put about half-gallon of anti-freeze in every week. No the thermostat was not changed nor the heater core. need help please! thanks in advanced!!!!

 

Could start with putting a thermostat in it. When you say going up a hill/mountain are you towing just driving?

Start simple and work your way up. Start at the thermostat, my money is on the radiator. My truck did the exact same thing, drank half a gallon of coolant a week, and then eventually it got to the poijnt going down the road for 2 miles and the truck red-lined at over 250*. Radiator was clogged, put a new one in and booyah truck idled at 180* I put a 180* t-stat in mine.

 

yea just normal driving not towing. im gunna try a stat once and see but like you said its probably the radiator. i also thought about air pockets still in the system somewhere but it should of worked its way out.

 

you'd be surprised how long the can stay in the system, especially if you have leaking rear freeze plugs.