I have a 04 QC 4.7 ram 1500. It all of a sudden started to overheat. I turn on the truck the temp goes past 1/2 way, so i heard turning on the heater will lower the temp, so i turn on the heat and it blows out cold air. Eventually when the truck has been running the usual amount of time for it to warm up the heater will work just fine but it still overheats to the point i get the check gauges indicator. Once i start driving and i'm not stuck in traffic anymore it never goes past 1/2 way and everything works great what could this be. Thank you!

 

Start with the basics. Check the level of coolant in the radiator & reservoir. If all is well there and you can see no visible signs of a coolant leak, then it'd be time to replace the thermostat. It's a relatively inexpensive part (usually under $10) and about a 15 minute process to remove the old one and replace. It's possible that your original thermostat is stuck closed and not allowing coolant through to the engine.

 

ok this morning i went outside and removed the radiator cap and began filling the radiator with a turkey baster by sucking the coolant out of the reservior and putting it into the radiator. I drained most of the radiator and turned on the truck and all was goood. As far as i saw the temp took a while to heat up usually within the first few minutes it would shoot right up but it stayed at cold. I'm letting my Fiance drive it right now so she can be safe with all the snow so she'll update me later and i'll let you guys know. Thanks for all the info and help.

 

yep that solved it thanks. I never knew the radiator had to be filled. I always thought that the reservoir took care of that, well you learn something new everyday.